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*^ACIIi

M E N T SC&^ ■^

or ,

CHEMISTRY,

NEW SYSTEMATIC ORDER,

MODERN DISCOVERIES.

ILUlSTRATSJi ST •mUaiXiJ COfFEXfLATLS.

BY Mr LAVOISIER,

Member of tbe AndeiDin mA S«cietiei of Puii, I^ndon, Oileiu,
Bulopia, BiGl, Fhilndelphin, Hmerlem, Manchcftcr, Sec. 8cc,

T KAMI L ATI D>I.OK TBI FKINCB

Bt ROBERT KERR, F. R. & A. SS. Edim.

Membei nf the Kojal CoUe|< ef Siugcniu, and cf [lie Kayal FbyGnl

Society of Edinburgh.

FOURTH EDITION.

WITH MOTES, TABLES, AND COHSrOERABLE ADDITIONS.

EDINBURGH-.
PRINTED FOR WILLIAM CREECH; and sold is

LONDON BT G. G. & J. ROBINSON, AND T. KAY.

H,DCC,XC1X.
■J

- >wV

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Sv

* \ V VN

>^ *

UBR4Pr Of THE

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•0 /;-'/i/r/?.9/./,

asA-fcl'^

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V-» '•

ADVERTISEMENT

TRANSLATOR,

TO THE THIRD EDITION.

THE very high chiradcr which Mr La-
voifier has fo deferredly acqiured as
a chemical philo(bpher, and the ereai re-
volution which he has efleded in the theo-
ry of chemiflry, had long made it much
defired by all the cultivators of phyj:cAl
fcience, to have a conneded account of his
difcoveries, and thofe of other chemicil
philofbphers, on which his opimous are
founded, together with an accurate expo-
fition of the new theory, or rather of the
regular concatenation of fads, which he
has eftablifhed, in coniequence of theie dii-
coveries, made by himlelf and others- For
the performance of this arduous underta-
king, no one could poflibly be better qua-
lified than Mr Lavoifiet himfelf : He
not only thoroughly conver(ant in the
coveries of other philofo{^rs, having/

A ^ i^

ri ADVERTISEMENT.

infinite pains, repeated all their importam
experiments, and fo varied moft of them as
to bring their refults into a much clearer
view, but was himfelf the author of many
important difcoverles. The hiftory, there-
fore, of thefe difcoveries, and their proper
arrangement, for conveying an eicad idea
of the new theory which he had deduced
from them, eould not, certainly, have been
given to the world fo well, or with fo much
propriety, by any other perfon.

This great defideratum in the hifl<»:y

and fcience of chemiftry, was accomplilhed

1 the year 1789, by the pubVication of the

ADVERTISEMENT. viJ

A new edition of the original having ap-
peared at Paris in winter 1792-3, ex{w^6ta-
tions were formed that the author might
have made coniiderable improvements ;
but, from a correfpondence with Mr La-
voifier, the tranflator is enabled to fay, that
the new edition, having been printed with-
out his knowledge, is entirely a tranfcript
from the former.

Some very material additions, though
not numerous, have been made by the
tranflator In this edition, relative to cer-
tain difcoveries which have taken place
in fome parts of chemiftry fince the publi-
cation of the original ; but as thefe are all
diftvndily marked in their proper places in
the courfe of the work, it is not ncccff-iry
to enuTnerate them here.

In the original, Mr Lavoifier employs -
the fcale of Reaumeur's thermometer, for
defcribing the degrees of temperature in his
experiments : In the fecond and third edi-
tion of this tranflation, thele are uniform-
ly transferred into their correfpondcnt de-
j^Teesonthe fcale of Fahrenheit, which lat-
ler is univerfally ufed by the Britilhphi-
lofophers. The weights employed by Mr
A A Lavoilier

viii ADVERTISEMENT.

Lavoifier for detailing the ingredients and
refults of his various experiments, are. In
the original, exprefled in the cuftomary
aliquot parts of the Paris pound, poidt de
marc, which is divided very difierently
fr<Mn the Englifh poimd, either troy or a-
verdupois : To render thefe weights fully
intelligible to the Britilh reader, they are
all, in this edition, reduced to decimal
fradlions of the pound, which will ferve
for all denominations.

In the courfe of the tranflatlpn, feveral
ex[danatory notes are added j principally
for the purpofe of rendering the dodrines

ADVERTISEMENT. ix

with thcfe limited intentions, it is the beft
body of chemical philofophy extant.

In a fmall number of places, the tranf-
lator has taken the liberty of throwing
to the bottom of the page, in notes, feme
parenthetical exprcffions, not diredly con-
neded -with the fubjed, which, in their o-
riginal place, rather tended to conflife the
lenle : Thefe, and the original notes of the
author, are diftinguiihed by the letter A j
and to thofe which the traoilator has ven-
tured to add, the letter T is fubjoined.
Some difcoveries, which have been made
in various parts of chemiftry fince the pub-
lication of the original, are added in this
tranflation in their proper places.

Mr Lavoifier has given, in an appendix, •
feveral very uleful tables, for facilitating
the calculations now neceflary in the ad-
vanced ftate of modem chemiftry, where-
in the moft fcrupulous accuracy is requi-
red: Thefe are now as indifpenfibly requi-
fite to the operations of the chemical phi-
lofopher, as the Ephimerides, and Nautical
Almanacks, and Logarithmic Tables, are to
the Navigator, Aftronomer, and Geome-
trician. Thefe tables are all retained in
this

reduced ^^

X ADVERTISEMENT.

this tranilation ; being, however, red
to the ftandai'ds of Britiih weights and
meafures, with proper rules for making
the ncceflary convcrtions from the weights
and meafures of FraiKe; And the tranflator
is proud to acknowledge his obligations to
the learned Profeflbrof Natural Philofophy
in the Univerllty of Edinburgh, and to
his friend Dr Rotheram *, who kindly fup-
plied him with the necelTary infonnatiou,
and took the trouble of making a number
of very laborious calculations, for this
purpofc. With the fame afiiflance, feveral
very ufeful additional tables have been
given in the Append!.-;, which need not
be here enumerated, as they will diftind:-
ly apjjear in their proper places.

POSTSCRIPT to the Third Editim.

THE Philorophical World has now infi-
nitely to deplore the tragical and untimely"
death of the great Lavoisier ; who has
left a rare example of fplendld talents and
great

* I'ornierly AfTiflant to Dr Black. Profi (for of Cliemif-
try in the Unii'eriity of Edinburgh, and now I'tofelTor of
Natural Piiilofophy in the UniverCiy of

I

ADVERTISEMENT. xi

great wealth, at the fame time immerfed
in numerous and important public employ-
ments, which he executed with diligent in-
telligence, and devoting his princely for-
tune and vaft abilities to the fedulous cul-
tivation and moft fuccefsful improvement
of the Sciences^ If the fanguinary tyran-
ny of the monfler Robefpierre had com-
mitted only that outrage againft eternal
Juftice, a fucceeding age of the moft per-
fect gevemment would fcarcely have fufE^
ced, to France and to the world, to repair
the prodigious injury tliat iofs has produced
to chemiftry, and to all the fciences aud
economical arts with which it is conneded.
Had Lavoifier lived, as exprcfled in a.
letter received from him by the tranllator
a fnort while before his mallacre, it was
his intention to liave republiflied tliefe Ele-
ments in an entirely new form, compoflng.
a Complete Syftem of Philofophical Che-
miflry : And, as a mark of his fatisfadioii
with the fidelity of this tranllation, he pro-
poled to have conveyed to the trannator,
flicet by flieet as it Ihould come from the
prefs, that new and im^aluablc work, alas I
now for ever loft*.

PREFACE

PREFACE

A U T H O lU

^V ITHEN I began tbe foOowiiig Work, m/
▼ ▼ oolj objcd WIS to extend and explain
moie fullv the Memoir which I read at the pu-
blic meeting of the Academy of Sciences in the
month of April 1787* 00 the neceffity of re-
Conning and completing tbe Nomendature of
Chemiftry. While engaged in diis employment,
I perceived, better than I had ever done before,
the jullice of the following maYim^ of the Abbe
de Condillac, in his fyftem of Logic, and fome
other of his works.

*€

" We think only through the medium of
words« — Languages are uue analytical me-

" thods.

PREFACE. xiii

^' thods. — Algebra, which is adapted to its pur-
** pofe in every fpecies of exprel&on, in the
** moil fimple, moft exad» and beft manner
«< poffible, is at the fame time a language and
" an analytical method.— The art of reafoning
<' is nothing more than a language well arran-
•' ged."

Thus, while I thought my felf employed only
in forming a Nomenclature,, and while I propo-
fed to myfelf nothing more than to improve the
chemical language, my work transformed itfelf
by degrees, without my being able to prevent
it, into a treatife upon the Element^ of Che-
miftry.

The impoflibility of feparating the Nomen-
clature of a fcience from the fcience itfelf, is
owing to this, that every branch of phyfical fci-
ence muft confift of three things ; the feries of
fadts which are the objedls of the fcience ; the
ideas which reprefented thefe fafts ; and the words
by which thene i.ieas arc expreffed. Like three
impreffions of the fame feal, the word ought to
produce the idea, and the idea to be a pidure of
the fad. And, as ideas are preferved and com-
jnunicated by means of words, it necefTarily fol-
lows,

PREFACE.

Jows, that we cannot improve the language of
any fcience, without at the fame time improving
the fcience itfclf ; neither can we, on the other
hand, improve a fcience, without improving tlie
language or nomenclature which belongs to it.
However certain the fadls of any fcience may
bs, and however juft the ideas we may have
formed of thefe fafts, we can only communicate
falfe or imperfect impreffions of thefe ideas to
others, while we want words by which they may
be properly exprefled.

To thofe who will confider it with attention.

the firft pari of this treatUc will afford frequent

^ wants, the fcnl

PREFACE. XV

wants, the fcnfation of want exciting the idea of
the objed by which it is to be gratified. In
this manner, from a leries of fenfations^ obfcrva-
ttoos, and analyfes, a fuccefiivc train of ideas a-
rifes, fo linked together, that an attentive obfcr-
ver may trace back, to a certain point, the order
end conneclion of the whole fum of humiin kiion -
ledge.

When we begin the lluily of any fcjencc,
, we are in a fituation, refpediing that Icience,
fimilar to children; and the courfe by uhidi
we have to advance, is prccifely the fame which
Nature follows in the formation of their ideas.
In a child, the idea is merely an effefl produced
by a fcnfition ; and, in the fame manner, in
commencing- the ftudy of a phyfical fcience, we
ought to form no idea bnt what is a neceffary
confequence,. and immediate eflefl, of an capc-
riment or obfervation. Befides, he who enters
upon the career of fcience, is in a lets advanta-
geous fituation than a child who is acquiring
his firft ideas. To the child, Nature gives va-
I rious means of rectifying any mittakcs he may
commit rcfpeding the falutary or hurtful quali-
ties of the objefts which furround him. On
every occafion his judgments are correfted by
experience ;

iviii PREFACE.

ftudy of chemiftry thoroughly to underftand
-them. Hence I have been obliged to depart from
the order ufually obfcrved in courfcs of lectures
and treatifcs upon chemiftry ; which always aC-
I'ume the firft principles of the fcience as known,
whereas the pupil or the reader fhould never be
fuppofed to know them till they have been ex-
plained in fubfequent leirons. In almolt every
inilance, chemical authors and leflurers begin
by treating of the elements of matter, and by
explaining the table of affinities; without con-
tldering, that, In fo doing, they muft bring the
principal phenomena of chemiftry into view at
the very oiillet ; They make ufe of terms which
have not been defined, and fuppofc the fcience
to be underftood by the very perfons they are
only beginning to teach.

It onght likewifc to be confidered, that very
little of chemiftry can be teamed in a firft courfe,
which is hardly fufllcient to make the language
of the fcience familiar to the ears, or the appara-
tus familiar to the eyes. It is almoft impoflible
to become a chemift in Icfs than three or four
years of conftant application.

Thefc inconveniences arc occafioned, not fo
much

PREFACE; lix

much hj the nature of the fubjed, d$ by the
method of teaching it ; and, to avoid them, I
was chiefly induced to adopt a new arrangement
. of chemiftry, which appeared to me more (:on-
fonant to the order of Nature. I acknowledge^
however, that in thus endeavouring to avoid
difficulties of one kind, I hstve found myfdf in-
volved in others of a different fpecies, feme of
which I have not been able to remove j but I
am perfuaded, that fuch as remain do not arife
from thfe nature of the order I have adopted,
but are rather confequences of the imperfeftion
under which chemiftty ftill labours. This fciencc
has many chafms, which interrupt the feries
of fafts^ and often render it extremely difficult
to reconcile thefe with each other : It has not,
like the elements of geometry, the advantage of
being a complete fcience, the parts of which are
all clofely connedled together : Its actual pro-
grefs, however, is fo rapid, and the fads, under
the modern doArine^ have aflumed fo happy an
arrangement, that we have ground to hope, even
in our own times, to fee it approach near to the
higheft ftate of perfection of which it is fufcep-
tible.

The rigorotis law from which I have never

B z deviated,

PREFACE.

deviated, of forming no concluHom tvhich art
not fully warranted by experiment, and of never
fupplying the abfence of fafts, has prevented me
from comprehending in this work the branch
of chcmlllry which treats of affinities, although
it is perhaps the heft calculated of any part of
chemiftry for being reduced into a completely
fyflematic body. Meffrs GeofFroy, Gellert, Berg-
man, Scheele, De Morveau, Kirwan, and many
others, have collefted a great number of particu-
lar fafts upon this fubjecH:, which only wait for a
proper arrangement ', but the principal data are
flill wanting, or, at leaft, thofe we have are ei-
ther not fufficiently defined, or not fufficiently
proved, to become the foundaticHi for a fo very
important branch of chemillry. This fcience of
affinities, or eleflive attradions, holds the fame
place with regard to the other branches of che-
miftry, that the higher or tranfcendental geome-
try does with refpeft to the fimpler and elemen-
tary part ; and I thought it improper to involve
thofe firaple and plain elements, which I fljtter
myfelf the greateft part of my readers will ealily
underftand, in the obfcurities and difficulties
which ftill attend that other very iifeful and ne-
ceflary branch of chemical fcience.

Perhaps a fentiment of felf-love may, without

^H my perceiving

I

PREFACE. xxi

my perceiving it, have given additional force to
thefe reflexions. Mr de Morveau is at prefent
engaged in publiftiing the article Affinity in the
Methodical Encyclopcedia; and I had more rea-
fops than ooe to decline entering upon a work
in which he is employed.

It will, no doubt, be a matter of furprifc, that
in a treatife upon the elements -of chemiftry,
there fhould be no chapter on the conftituent
and elementary parts of matter ; but I may
here obferve, that the fondnefs for reducing all
the bodies in nature to three or four elements,
proceeds from a prejudice wiiich has defcended
to us from the Greek Philofophers. The notion
of four elemenlsi which, by the variety of their
proportions, compofe all the known fubftances
in nature, is a mere hypothefis, aiUimcd long
before the firft principles of experimental philo-
fophy or of chemiftry had any exiftence. In
thofe days, without pofleffing faSs, they fram-
ed fyftems ; while we, who have collefted fad-s,
ieem determined to reje(5t even thefe, whea
they do not agree with oQr prejudices. The
authority of thofe fathecs of human philofophy
ftill carry great weight, and there is reafon to
B3 *«w

i«i»

PREFACE.

fear that it will even beac ^ard upon generations

yet tQ conjc.

It is very remarkable, notwithftanding the
puihber of philofophical chemlfts who have fup-
ported the doiflrine of the four elements, that
there is not one who has not been led, by the
evidence of feds, to admit a greater number of
elements into their tt^eory. The firft chemical
authors, after the revival of letters, conGder-
pi fulphur and fait as elementary fubAances en-
tering into the compofition of a great number
pf bodies ; hence, infiead of four, they admit-

^H ftrtclly rigorous analyli!

^H modern pbiloropby.

I ^'

H natu:

m to di

PREFACE. xxiii

hich is required hy

All that can be faid upcin the number and
nature of elements is, in my opinion, confined
to difcuflions entirely of a metaphyfical nature.
The fubjeft only furnilhes us with indefinite
problems, which may be folved in a thouland
dilTcrent ways, not one of which, in all probabi-
lity, is confiftent with nature. I fliftll, therefore,
only add upon this fubjefl, that if, by the term
elements, we mean to exprefs thofe luiiple and
indivifibie atoms of which matter is compofetl,
it is extremely probable we know nothing at all
about them ; but, if we apply the term elements
or principles of bodies, lo exprefs our idea of the
laft point which analylis is capable of reaching,
we muft admit, as elements, all the fubftancea
into which we are able to reduce bodies by de-
compofitiun. Not that we arc entitled to affirm,
that thefe fubftances which we confider as finiple,
may not thcmfelves be compounded of two, or
even of a greater number of more fimple princi-
ples; but fince thefe principles cannot be fe-
pafated, or rather fince we have not hitherto
difcovered the means of feparating ihem, they
aft with regard to us as fimple fubftances, and
B 4 wc

%%iv PREFACE.

we ought never to fuppofe them compoundcfl
pntil experiment and obfervation have prored
them to be fo.

The foregoing refleiftiojis upon the prbgrefs
p[ chemical idea$ naturally apply to the wor^s
bj which tbefe i4eaB ^re expre0'cd. Guided
by the wprjc which, iq the year 1787, IVI^iTre
de MorTpau, BerthoUet, de Fourcroy, and I
conipofed upon the I^omepcUture of Cbemiflry,
:{ bare endeavoured, as onicb as pp^ble, to de-
9iomin4te limpk bodies by Q mple terms, and Z
was naturally led to qame thefe fi^rft, ^t vrill be
rcculkiitetl. thitt we were oblieed 10 retain that

I

I

PREFACE. MV

er perhaps oppolite qualities. We made no
fcruple, in this cafe, of fubftiluting other names
in their room, and the greater number of theie
were borrowed from the Greek language. We'iC
endeavoured to frame them in fuch a manner
as to exprefs the moft general and the mod
charai5lcri(\ic quality of the fubftances ; and this
was attended with the additional advantage both
of aOIfting the memory of beginners, who find
it difficult to remember a new word which has
no meaning, and of accuftoming them early to
admit no word without connefling with it fome
determinate idea.

To thofe bodies which are formed by the
union of feverd firaple fubftances, we gave new
names compounded in fuch a manner as the
nature of the fubftances dircded ; but, as the
number of known double combinations is already
Tcry confiderable, the only method by which we
could avoid confufion, was to divide thefe into
claffes. In the natural order of ideas, the name
of the clafs or genus is that which expreffes a
quality common to a great number of indivi-
duals ; the name of the fpecies, on the contra-
ry, expreffes a quality peculiar to certain indivi-
(iuals only.

Tbefo

xjti-i PREFACE.

Thefe diftinClioas are not, as fome may ima-
gine, merely metapliyfical, but are eftablidjed
by Nature. " A child," fays the Abbe de Con-
dtllac, '* is taught to give the name tree to the
" firft which is pointed out to him. The next
" tree he fees prefents the fame idea, and he
" gives it the fame name. This he does Ukewife
•' to a third and a fourth, till at laft the word
•' tree, which he at tirll applied to an individual,
** comes to be employed by him as the name of
" a clafs or a genus ; it becomes an abftrat^ idea,
" which comprehends all trees in general. But
■' when he learns that all trees do not ferve the
" fame purpofe, that they do not all produce
" the fame kind of fruit, he foon diftinguifties
" them by fpecific and particular names." This
is the logic of all the fciences, and is very na-
turally applicable to chcmiftry.

The acids, for example, are compounded of
two fubftances, which we confider as fimple ;
the one conflitutes acidity, and is common to all
ncids, aud, from this fubftaiice, the name of the
clafs or the genus ought to be taken ; the other
is peculiar to each acid, and diftinguiflies it from
the reft, and from this fubftance is to be taken
the name of the fpecies. Bat, in the greater
number of acids, thefc two conftiiuent ele-

^f ments

PREFACE.

I

ments, the acidifying principle, and that which
it acidifies, may exift in diflerent proportions,
conftitutingall thepoflible points of equilibrium
or of faturaiion. This is the cafe in the fulphu-
ric and the fulphurous acids ; and thefe two
ftates of the fanie acid we have marked by vary-
ing the termination of the fpeciiip name.

Metallic fubftances which have been expofed
to the joint adion of the air and of fire, lofc
their metallic luftre, increafe in weight, and af-
fume an earthy appearance. In this ftate, like
the acids, they are compounded of a principle
which is common to all, and of one which is pe-.
cuUar to each. In the fame way, therefore, we
have thought proper to clafs them under a ge-
neric name, derived from the common prin-
ciple ; for which purpofe, we have adopted the
term oxyd ; and we difiinguifh them from each
other by the particular name of the metal to
which each belongs.

Combuftible fubllances, which tn acids and
metallic oxyds are fpecific and particular prin-
ciples, are capable of becoming, in their turn,
common principles of a great number of com-
pounds. The fulphurous combinations have
been

goniii PREFACE.

been loi% the only known ones in this kind :
Now, bowever, we know, from the experiments
of Mefirs Vaodermonde, Monge, and Berthol-
let, that carbon may be combined with iron,
and perhaps with feveral other metals ; and that,
from this combination, according to the propor-
tions, may be produced Heel, plumbago, 8cc.
We know likewife, from the experiments of M,
Pelletier, that phofphoius may be combined with
a great number pf metallic fpbftances. Thefe
difTerent combioations we have claiTed under ge-
neric names taken from the common fubftance,
with a termination which marks this analogy,

■^ earthy, or tnf

I

I

R. E F A C £. xxix

earthy, or metallic bafis, which determines the
particular fpecies of fait. Here we derived the
name of each clafs of falls from the name of the
acidifiable principle common to all the indivi-
duals of that clafs ; and diftinguiHied each fpecies
by the name of its peculiar faline, earthy, or me-
tallic bafis.

A fait, though compounded of the fame three
principles, may, ncverthelefs, by the mere diffe-
rence of their proportion, be in three different
ftates of faturation. The nomenclature wc
have adopted would have been defe<^ive, had it
not dxpreffed thefe different flates ; and this we
attained chiefly by changes of termination uni-
formly applied to the fame ftate of the different
falts.

In Ihort, we have advanced to far, that from
the name alone may be inftantly found; what
the combuftable fubftance is which enters into
any (ombination; whether tliat combuftible fub-
Itance be combined with the acidifying prin-
ciple, and in what proportion ; what is the ftate
of the acid ; with what bafis it is united -, whe-
ther the faturation be cxaft, or whethsr the acid
or the bafis be in escefs.

t

PREFACE.

It taaj eafilj be fitppoied that it was oot pol-
ifale to atsain aU tbde different objc^ without
Atpuitiu^ ia fbme infiaoce^ &om eflabli&ed
mttnm^ sod adopting terms which, at 6tA fight,
in37 ■ppear uncouth and barbarous. But we
confidcred that the ear is foon habituated to
new words, efpecitily when thej arc conneaed
with a general and rational Ijftcm. The names,
bcfides, which were formerly employed, fuch as
foveder «f afgarotb, /alt cf oUmhrotb, pompiniix,
pbngad<*K rjeater, lartntb sdaeral, colcotbar, and
many others, were ocither lets barbarous nor
lefs uncommon. It required a great deal of prac-
tice, and no fmall degree of memory, to recoUciJl
ibc fubtlances to which they were applied ; much
more to recollect the genus of combination to
which tliey belonged. The names of oil of tar-
tar per diHfaJKait **i tf «urT«/, iuttrr e/ arfinic
and of antunonjr,Jhwcrj ^ xnc &c. were ftiU
more improper, becaufe tbey fuggefted falfe
ideas j for, in the whole mineral kingdom, and
particularly Li the metallic clafs, there exifts no
fuch thing as butters, oils, or floTrcrs ; in fliort,
the fubtlances to which ihcfe fallacious name?
were given, are rank poifons.

When

P R E E A C E.

When we publifhed our eflay on the Nomen
clature of Cheraiftry, we were reproached for
having changed the language which was fpoken
by our mailers, which thej flumped with their
authority, and have handed down to us. But
thole who reproach us on this account, have for-
gotten that Bergman and Macquer urged us to
make this reformation ; In a letter which the
learned Profeffor of Upfal, M. Bergman, wrote,
a (hott time before he died, to Mr Mor\'eau, he
bids him. Jpa re no improper names ; tbofe who are
learned, ivill alwayt be learned, and iboje who
are ignorRnt ivill thus iearnfooner.

There U an objeflion to this work, which is
, perhaps better founded \ that I have given no
account of the opinions of thofe who have gone
before me, and hare only flatcd my own with-
out examining tliofe of others. By this I have
been prevented from doing that juftice to my
affociates. and more efpecially to foreign che-
mifts, wliich I wiftied to render them. But I
befiKch the reader to confider, that, if I had fil-
led an elementary work with a multitude of quo-
tations, if 1 had allowed mjfclf to enter into
long dilVertations en the hiflory of the fciencc.
aad the works of thofe who have ftudied it, I
muft

XKxii PREFACE.

muft have lofl: fight of the true objed I h^ id
view, and (hould have produced a work extceme-
ly tirefome to beginners.

It is not the hiftory of the fcience, or of tbfc
human mind, that we are to atteinpt in an ele-
mentary treatife. Our only aim Ihould be ealc
and perfpicuity, and With the utmoft care t6
keep every thing out of view which may draw
aiide the attention of the ftudent. It is a road
which we fhould be Comiriudly rendering more
finooth, and from which we muft eiideavouir to
remove every obllacle which can occafion delay.
The fciences, from their own nature, prefent

PREFACE. xjtxiii

iBg, to each other, has eftablifhed between us
a fort of community of opinions, in which it is
often difficult for every one to know his own.

Thefe remarks on the order which I thought
myfelf obliged to follow in the arrangement of
proofs and ideas, are to be applied only to the
firft part of this work. It is the only one which
contains the general fum of the do<ftrine I have
adopted, and to which I wiflied to give a form
completely elementary.

The fecond part is compofed chiefly of tables
of the nomenclature of the neutral falts. To
thefe I have onlyadded general explanations, the
object of which is to point out the moft fimple
proceffes for obtaining the different kinds of
known acids. This part contains nothing which
I can call my own, and prcfents only a very
Ihort abridgment of the refults of thefe procef-
fes, extradted from the works of different au-
thors.

In the third part, I have given a dcfcription,
in detail, of all the operations connected with
podern chcmiftry. I have long thought that a

C worK

PREFACE.

work of this kind was much wanted, and I am
convinced it will not be without its ufe. The
method of performing experiments, and particu-
larly thofe of modern chemiftry, is not fo general-
]y known as it ought to be ; and had I, in the dif-
ferent memoirs which I have prefented to the
Academy, been more particular in the detail of
the manipulations of my experiments, it is pro-
bable I Ihould have made myfelf better under-
ftood, and the fcience might have made a more
rapid progrefs. The order for the different mat-
ters contained in this third part appears to me
almort arbitrary ; and the only one I have ob-
fcrved is to clafs together, in each of the chapters
of which it is compofed, thofe operations which
are moft connet^ed with one another. I need
hardly mention, that this part could not be bor-
rowed from any other work, and that, in the
principal articles it contains, 1 could not derive
affiftance from anything but the experiments
which I have made myfelf.

I fhall conclude this preface by tranfcribing,
literally, fome obfcrvations of the Abbe dc Con-
dillac, which I think defcribe, with a good deal
of truth, the ftate of Chemiftry at a period not

far

PREFACE. XXXV

far diftant from our own. Thefe obfervations
were made on a different fubjedl ; but they will
not on this account, have lefs force, if the appli-
cation of them be juft.

* Inftead of applying obfervation to the things

* we wilhed to know, we have chofen rather to

* imagine thepi* Advancing from one ill-found-

* ed fuppofition to another, we have at laft be-

* wildered ourfelves amid a multitude of errors.

* Thefe errors, becoming prejudices, are, of

* courfe, adopted as principles, and we thus be-

* wilder ourfelves more and more. The method,

* too, by which we condud our reafouings is

* abfurd \ we abufe words which we do not un-

* derftand, and call this the art of reafoning.

* When matters have been brought this length,

* when errors have been thus accumulated, there
' is but one remedy, by which order can be re-

* ftored to the faculty of thinking ; this is, to
' forget all that we have learned, to trace back

* our ideas to their fource,to follow the train in

* which they rife, and, as Lord Bacon fays, to

* frame the human underllanding anew.

* This remedy becomes the more difficult, in
*• proportion as we think ourfelves the more

C! 2 * learned.

xsxvi P R E F A C t.

* learned. Might it not be thought, that works
' which treat of the fciences with the utmoft per-
' fpicuity, and with the greateft order and prcr
' ciiion, muft be underllood by every body ?

* The faft is, thofe M'ho have never ftudied any
' thing will underftand them better than thofe

* who have ftudied a great deal, and efpecially
' than thofe who have written a great deal.'

In another place the Abbe de Condillac adds :

* But, notwitbftanding, the fciences have impro-

* ved, becaufe philofophers have applied theni-
' felves with more attention than formerly to ob-

* ferve Nature, and have communicated to their

C O N T EN T S.

PART FIRST.

Of the Formation and Decompofition of
Aeriform Fluids— of the Combuftion of
Simple Bodies — and the Formation of
Acids. Page 49

CHAP. I — Of the Combinations of Caloric, and the
Formation of Elaftic Aeriform Fluids or Gaffes, ibid.

CHAP. II. — General Views relative to the Formation
any Compofition of our Atmofphcre, 74

CHAP. III.— Analyfis of Atmofpheric Air, and its
Diviiion into two Elaftic Fluids 5 one fit for Refpi-
ratipn, the other incapable of being Refpired, 80

CHAP. IV. — Nomenclature of the feveral Conftitu-
ent Parts of Atmofpheric Air, 97

CHAP. V. — Of the Decompofition of Oxygen Gas
by Sulphur, Phofphonis, and Carbon, and of the
Formation of Acids in general, 103

CHAP. VI. — Of the Nomenclature of Acids in ge-
neral, and particularly of thofe drawn from Nitre
and Sea-Salt. 116

CHAP. VII. — Of the Decompofition of Oxygen
Gas by means of Metals, and the Formation of Me-
tallic Oxyds, 129

C 3 CHAP.

CONTENTS.

CHAP. VIII.— Of the Radical Principle of Waicr,

and of its Dccompofition by Charcoal and Iron, P. 135
CHAP. IX — Of the Quantities of Caloric difen-

gaged from different Species of Combullion, ijo

Combnilion of Phofphoi iis, 154

SECT, l.-— ConibuQion of Ctiarcoal, 153

SECT. 11.— Combunion of Hydrogen Gas, ib.

SECT. Ill— Formation of Nitric Acid, 156

SECT. IV.— Conibuaion of Wax, IJ9

.SECT, v.— Combuificn of Olive Oil, 160

CHAP. X.— Of the Combinations of Combuftible

Subllnnces with each other, 163

CHAP. XI.— Obfervations upon Oxyds and Acids
with feveral Bafcs, and upon the CompoJicion of
Animal and Vegetable Subflances, 17*

CHAP. XIL— Of the Decompofition of Vegcuble
and Animal Subftances by the AClion of Fire, ijS

CONTENTS. xxxix

PART II.

Of the Combinations of Acids with Sali-
fiable Bafes, and of the Formation of
Neutral Salts, P^ge 243

INTRODUCTION, ib.

Table of simple Subftances, 245

SECT. I. — Obfervations upon Simple fubftances, 146
Table of Compouod Oxydable and Acidifiable
Bafes, 249

SECT. II.— 'Obfervations npon Componnd Radicals, 250
( SECT. III. — Obfervations upon the Combinations of
Light and Caloric with different SubUances, 252

Table of the Combinations of Oxygen with the
Simple Subftances, to face 255

SECT. IV. — Obfervations upon thefe Combina-
tions, 255

TABLE of the Combinations of Oxygen with Com-
pound Radicals, 260

SECT, V. — Obfervations unon thefe Conibinarions, 261

Table of the Combinations of Azot ivith the
Simple Subflances, 264

SECT. VI. — Obfervations upoli thefe Combinations
of Azot, 265

TABLE of the Combinations of Hydrogen with
Simple Subitances, 268

SECT. VII. — Obfervations upon Hydrogen, and its
Combinations, 269

TABLE of the Binary Combinations of Sulphur

with the Simple Sublhnces, ^7*

C 4 SECT,

CO NTENTS.

SECT. Vin.— Obferrations on Sulphur, and its
ComtMnatiDos, Page 275

TABLE of the Binary Comhinationi of Phofpborm
widi Simple Subftancet, 374

SECT. IX — ObfervatioKs on Phofphoms and its
CombinatioDS, '375

Table of the Binary Combinations of Carbon, 177

SECT. X. — Obfervations upon CarboRt and its Com-
binatiom, 378

SECT. XL— Obfervations Upon the Muriatic, Flu-
oric, and Boracic Radicals, and theit Combina-
tions, 379

SECT. XIL— Obfenrations upon the ConbiBatioDs
of Metals with each other, a8o

TABLE of the Combinations of Azot, in the Sute
of Nitrous Acid, with the Salifiable Bafes, aSx

TABLE of the Combinations of Azot, in ^the State

CONTENTS. i^

SECT. XVII.-^Obfcrvations npon Carbonic Acirf,
and its Combinations witli Salifiable Bafes, Page 309

TABLE of the Combinations of Mitriatk Acid, 303

TABLE of the Combinations of Oxygenated Muri-
atic Acid, 303

SECT. XVIIL — Obfervations upon Muriatic and
Oxygenated Muriatic Acid, and their Combina-
tions with Salifiable Bafes, 304

TABLE of the Combinations of Nitro-Muriaiic
Acidy 307

SECT. XIX. — Obfervations upon Nitro-Muriatic A-
cid, and its Combinations with Salifiable Bafes, 308

TABLE of the Combinations of Fluoric Acid, 3x0

SECT. XX. — Obfervations upon Fluoric Acid, and
its Combinations with Salifiable Bafes, 311

TABLE of the Combinations of Boracic Acid, 313

SECT. XXL — Obfervations upon Boracic Acid, and
its Combinations with Salifiable Bafes, 314

TABLE of the Combinations of Arfeniac Acid 317

SECT. XXIL — Obfervations upon Arfeniac Acid,
and its Combinations with Salifiable Bafes, 318

SECT. XXIIL— Obfervations upon Moljbdic Acid,
and its Combinations with Acidifiable Bafes, 320

SECT. XXIV.— Obfervations upon Tungflic Acid,
and its Combinations with balifi.ible Biifes, and a
Table of thefe in the Order of their AfHnitj, 32s

TABLE of the Combinations of Tart.irous Acid, 324

SECT. XXV. — Obfervations upon Tartaroiis Acid,
and its Combinations with Salifiable Bafes, 315

SECT. XXVL— Obfervations upon Mallic Acid,
and its Combinations with Salifiable Bafes, 327

TABLE of the Combinations of Citric Acid, 329

SECT. XXVIL— Obfervations upon Citric Acid,
and its Combinations with Salifiable Bafes, 330

TARLr.

CONTENTS.

TABLE of the CombiostioDs of P;ro.ligaous A-

cid. Page 331

SECT. XXVIII.— Obferrations upon Pyro-ligaous

Acid, and its Combtaations with Salifiable Ba£cs, 331
SECT. XXIX. — Obfervations upon Pjro-tartarous

Acid, and lu CombioatioDS with Salifiable Bafes, ib.
TABLE of the Combinationi of Pyro-mucous Acid, 334
SECT. XXX.— Obfervations upon Pyro-mucous A-

cid, and its Combinationi with Sali£able Bafes, 335
TABLE of tbe Combinations of Oxalic Acid, 336

SECT. XXXI.— Obfervations upon Oxalic Acid,

ftod its Combioations with Salifiable Bafes, 337

TABLE of the Combinations of Acetous Acid, to

face 338

SECT. XXXII.— Obfemtions upon Acetous Acid,

and its combinations with tbe Salifiable Bafts, 33S
TABLE of tbe Combinations of Acetic Acid, 342

C O N T E«J T S. xUii

Acid, and its Combioaitlon with Salifiable Bafes, ?• 35 2
TABIyE of the Combioatioos of Formic Acid, 353

SECT. XL. — Obfervacions upon Formic Acid, and

its Combinations with the Salifiable Bafes, 354

SECT. XLI. — Obfervations upon the Bombic Acid,

and its Combinations with Acidifiable Bafcs, 355

TABLE of the Combinations of the Sebacic Acid, ^^6
SECT. XLIL — Obfervations upon the Sebacic A*
cid, and its Combinations with the Salifiable Sa-
fes, 357
SECT. XLIIL-— Obfervations upon the Lithic Acid,

and its Combinations with the Salifiable Bales, 358
TABLE of the Combinations of the Pruilic Acid, 339
SECT. XLI V. — Obfervations upon the Pruflic Acid,

and its Combinations with the Salifiable Safes, 360
SECT. XLV. — Recapitulation of the foregoing Ob-
fervations on the Acids and their Combinations, 361
TABLE of the Order of Affinities of the SaliGable
Safes with the fevcral Acids, fo far as is hitherto
known, 364

TABLE of the Nomenclature of the Neutral Salts, 366

PART IIL

Defcription of the Inftruments and Opera-
tions of Chemiftry, - 369

INTRODUCTION. 369

CHAP. I. — Of the Inftruments neceflary for deter-
mining the Abfolute and Specific Gravities of So-
lid and Liquid Bodies, ^73

lliv

a O t^T E N t S.

CHAP. II. — Of Gazometry, or the Meafnremciie
of the Weight and Volume of Aeriform SubAaa-
ces. Page 38 i

SECT.I. — Of the Pneomato-chemical Apparatus, ib.

SECT.IL— Of theGaiometer, 386

SECT. 111.— Some other methods for Meafuring the
Volume of Gaffes, 397

SECT. IV. — Of the method of Separating the dif.
ferent Gaffes from each other, 401

SECT, v.— Of the neceffarj Correffions of the Vo-
lume of GalTes, according to the Prefliire of the
Atmofphere, 406

SECT. VI.— Of the Correaion relative to the De-
grees of the Thermometer, 413

SECT. VII.— Example for Calculating the Correc-
tions relative to the Variations of PrelTure and
Temperature, 415

CONTENTS. jdv

SECT. III. — Of Evaporation, Page 452

SECT. IV.— Of Cryftallization, 456

SECT. V .—Of Simple DiftiUation, 461

SECT. VI.— Of Sublimation, 465

CHAP. VI.— Of Poeumato^hcmical Diftillations,
Metallic Diflblutions, and fome other Operations
which require very Complicated Inftrumeots, 467

SECT. I. — Of Compound and Pneumato chemical

Diftillations, - ib

SECT. II.— Of Metallic Diflblutions, 475

SECT. 1 11.^ Apparatus neceflarjr in Experiments

upon Vinous and Putrefadlve Fermentations, 478

SECT. IV. — Apparatus for the Decompofition of

Water, 481

CHAP. VII.— Of the Compofition and Ufe of Lutes, 484
CHAP. VIII. — Of Operations upon Combuftion

and Deflagration, 491

SECT. I.^Of Combuftion in General, ib

SECT. II.— Of the Combuftion of Phofphorus, 495

SECT. 111. — Of the Combuftion of Charcoal, 499

SECT. IV.— Of the Combuftion of Oib, 503

SECT, v.— Of the Combuftion of Alkohol, 510

SECT. VI.— Of the Combuftion of Ether, 5 1 3

SECT. VII.— Of the Combuftion of Hydrogen Gas,

and the Formation of Water, JI4

SECT. VIII.— Of the Oxydation of Metals, 3 1 8

CHAP.IX.— OfDeftagration, 529

CHAP. X. — Of the Inftruments neceflaxy for Ope-
rating upon Bodies in very high Temperatures, 537
SECT.I.— Of Fufion, ib

SECT. II. — Of Furnaces, 539

SECT. III. — Of increafing the Aftion of Fire, by
ufing Oxygen Gas inftead of Atcnofpheric Air, 551

APPENDIX.

CONTENTS.

APPENDIX.

No. I.— Table for Converting Lines or Twelfth
farts of an Inch, tmd Fra&iona of Lincf, into
DecimBl Frafiioos of the Inch, P'ge. 557

No. II. — Tablk for Convening the Obferved
. Heights of Water in the Jars of (be Pneumaco-
Chemical Apparetm, expreHed in Inches and
Decimals, into Conefponding Heights of Mer-
cury, 5j8

No. Ill — Table for Converting the Ounce Mea<
fures ufed by Dr PrielUey into French and Eng-
lifh Cubical Inches, jj9

No. IV. — Additional. — Rdles for Reducing the
Degrees of Reaumeur's and of the Swedilli Ther-
mometer, into in correfponding Degrees of Fah-
renheit's Scale, j6o
-AiiniTioy.vj,.— RiJLES

I

CONTENTS.

xlvii

No, X.— TABLES for CoQyeiting Ounces* IXams,
and Grains, Troy, into Dccimak of the Troy
Poand of 12 Ounces, and for converting Deci-
mals of the Pound Troy into Ounces, &c. Page 587

No. XL— Table of the Englilh Cubical Inches and
Decimals correfponding to a determinate Troy
Weight of Di&illed Water at the Temperature of
55^, calculated from Everard's experiment, 590

No. XII^^Additional. — Table of the Compa-
rative Heats of difl^ent Bodies, as a&ertained by
Crawford, 591

No. XIII. — ^Additjokal*— Table of the Ingre-

. dients in the Neutral Salts, as determined by Eir-
wan, 592

ELEMENTS

OF CHEMISTRY.

I

tbis be a very fingular conclulion, it is impofCblc
to be denied.

It may be fuppofed, that, fince the particles of
bodies are thus continuidly impelled by heat to
fcparate from each other, they would have do
connexion between themfclves ; and that, of
confquence, there could be no foUdity in na-
ture, unlefs thele particles were held together
by foaie other power which tended to unite
them, and, fo to fpeak, to chain them together :
This power, whatever be its caufe, or manner
of operation, is named Attraftion.

Thus the particles of all bodies may be con-
(itlcred as fubjed to the action of two oppolite
powers, Repulfion and Altradioii, between
which they remain in eciuilibrio. So long as the
attiadive force remains ftronger, the body muft
continue in a (late of foUdity ; but if, on the
contrary, heat has fo far removed thtfe parti-
cles from each other as to place them beyond
Ihe fphere of attraftioa, they lofc the oohefion
they before had with each other, and the body
ceafcs to be folid.

Water gives us a regolar and conilant exam-
pleof thefe fafts. Whilfl below 32" of Fahren-
heit's fcale *t it remains folid, and is called ice.
D 2 Above

• Whenever the degree of heat occurs ifl the original,
[ it is Hated by ihc author accordinj to Reaumeuj's iher-

« ELEMENTS

Above that degree of temperature, its particles
being no longer held together by reciprocal at-
tradion, it becomes liquid ; and, when we raife
its temperature above 212°, its particles, giving
way to the repulfion caufed by the heat, aflume
the ftate of vapour or gas, and the water is
changed into an aeriform fluid.

The fame may be affirmed of all bodies in
nature: They are either folid, or liquid, or in
the ftate of elaftic aeriform vapour, according
to the proportion which takes place between
the attradive force inherent ia their particles,
and the repullive power of the heat adingupon
thefe ; or, what amounts to the fame thing, in
proportion to the degrees of heat to which they
are expofed.

It is difficult to comprehend thefe phenome-
na, without admitting them as the effeds of a
real and material fubftance, or very fubtile fluid,
which, infinuating itfelf between the particles
of bodies, feparates them from each other. Even
allowing that the exiftcncc of this fluid may be
hypothetical, wc Ihall fee in the fequel that it
explains the pha-nomeoa of nature in a very fa-
tisfaftory manner.

This fubftance, whatever it is, being the caufe
of

moaitter; but the Irandator has thought it more conve-
nient to ufe Fahrenheit's fcale, as more generally em-
ployed and UQderflood in Britain,— T.

OF CHEMISTRY.

I

of heat, or, in other words, the fenfation which
we call ixanntb, being caiifed by the accumula-
tion of this fubftHoce, we cannot, in Arid lan-
guage, iliftinguifli it by the terra beai, becaufe
the lame name would then very improperly cx-
prefs both caufe and etFeifl. For this reafon, in
the memoir which I pobliflied in 1777*, 1 gave
it the names of igneous fluid and matter of heat :
And, Cnce that time, in the work f publiilied
by Mr de Morveau, Mr BcrthoHet, Mr de Four-
croy, and myfelf, upon the reformation of che-
mical nomenclature, we thought it ncceirary to
rejcft all periphraftic expreiTions, which both
lengthen pbyfical language, and render it lefa
diftind, and which even frequently does not
convey fufficiently juft ideas of the objedl in-
tended. Wherefore, we have diftinguiftied the
caufe of heat, or that cxtiuiritcly elaftic fluid
which produces it, by the term of caloric. Be-
fides, that this expreflion fulfils our objecl in the
fyftem which we have adopted, it poflefTcs this far-
ther advantage, that it accords with every fpecies
of opinion; lince, llriclly fpeaking, we are not
obliged to fuppofe this to be a real fubftance, it
being fufficient, as will more clearly appear in the
fequel of this work, that it be conlidcted as the
D 3 I . , repnlfive

• CoUe^ian^P^^he I'rench Aca(Ie:ny cf Sciences fof
that year, p. 410.

t New Cticmical No'Heoc' attire.

54

ELEMENTS

repulfivc caufe, whatever that may be, whic
parates the particles of matter from each other;
fo that we are ftill at liberty to invcftigate its ef-
fetts in an abftraiS and mathematical manner.

In the prefent ftate of our knowledge, we are
unable to determine whether light be a modifi-
cation of caloric, or if caloric be, on the contra-
ry, a modification of light. This, however, is
indifputable, that in a fyftcm where only deci-
ded faifts are admifiible, and where we avoid, as
far as poflible, to fuppofe any thing to be, thai
i% not really known to exift, we ought provifion-
allyto diftinguifh, bydiftindl terms, fuch thing:;
as are known to produce ditferent effects. We
therefore diftinguifh light from caloric ; though
we do not therefore deny that thefc have certain
qualities in common, and that, in certain cir*
cumllances, they combine with other bodies al-
moft in the fame manner, and produce, in part,
the fame effedls.

What I have already faid may fuflice to de-
termine the idea affixed to the word caloric;
but there remains a more difficult attempt,
which is, to give a jufl conception of the man>
ner in which caloric ads upon other bodies.
Since this fubtile matter penetrates through the
pores of all known fubflances j fiiice there are
no vefTels through which it cannot efcape.^nd,
confequently, as there are none which are capa-
ble of retaining it ^ we can only come at the
knowledge

r

I

OF CHEMISTRY.

knowledge of its properties by effefls which are
fleeting and difficultly afcertainabJe. It U in
thofe things which we neither fee nor feel, that
it is cfpeciall/ necefliiry to guard againft the Ex-
travagancy of our imagination, which for ever
inclines t6 ftep heyond the bounds of truth, and
is very difficultly rcflraihed within the nawow
limits of fafts.

We have already feen, that the fame body
becomes folid, or fluid, or agriforfti, according
to the quantity of calorie hy which' it is pene-
trated* or, rnore 0riaiy, according as the rc-
pulfire force exerted by the caiotic is equal to,
ftron^, or weaker, than the' attrafliion of the
particles of the body it ajfls upcrt).' •.■hi'.::---jtli

Bat. if thcfe twoTJOwefstonly HxiftedjbidlW
would becomt liquid at an indivifibte-degree Bf
the thermometer, and would almoft' inftantanc-
oufly pafs from the folid ftate of aggregation tp
that of aeriform elafticity. Thus Water', for in-
ftance, at the very inilant when it ceafcg to be
ice, would begin to boil, and would be iran^
formed ii>to an aeriform fluid, having its parti-
cles fcattered' indefinitely through the furround-
ing fpace. That this-doet not happen* muft de-
pend upon the aftion of fomt Ihird'pbwcr: The
preSbre of the atmulphere prevents this repara-
tion, and caufes the water to remain in ihe li-
quid ft^e Until ralfed to the tempeVaturcinoica-
ft£i"W i 1 i^ bri "iTie fcalc of 'FaKr^rmcft^s thermo-
D 4 meter ;

56 ELEMENTS

meter ; the quantity of caloric which it receiv)
ip ihc lower temperatures being infufficient to

. overcome the prcflure of the atmofpherc.

Whence it appear>^, that, without this atmo-

j fpheric preffuie, we Ihould not have any perma-
nent liquid, and ihould only fee bodies in that
ftate of exiftence in the very inftant of melt-
ing y for the fmallell additional caloric would
then inftantly feparate their particles, and diffi-
pate them through the furrounding medium.
Befides, without this atmofpheric preflure, we
fliould not even have any proper aeriform fluids ;
becaufe the moment the force of attradion i&
overcome by the repulltve pi>wer of the caloric,
the particles of bodies would feparate themfelves
indefinitely, having nothing to give limits to

i their expanCon, uulels their own gravity might

[ colled them together, ib as to form an auno-

I fyhere.

Simple. reSe&ioo, upoa the mod common ex-
periments, is fufficient to evince the truth of
thefe pofitions. They are more particularly
proved by the following experiment, which I
publiDied in the Memoirs of the French Aca-
demy of Sciences for 1777, p. 426.
:- Having filled with Sulphuric Ether * a {mall
, -...li n t ^ . narrow

■/ ■ . I ■ tit.

* I Ihall dftcrwjtrds give a de&niiion, and cxplaia the

ptopetlieSjofthc liquor called Ethir; 1 lliallilitrefore only

premile

I

OF CHEMISTRY.

57

I

ntrrow glafs vcffel, A, (Plate VII. Fig. 17O,
Handing upon its ftalk P ; the vefltl, which 13
from twelve to fifteen lines diameter, is coveted
by a wet bladder, tied round m neck with fe.
veral turns of flrong thread ; foi- greater fecurity,
a fecond bladder is fixed over the firft. The
Teflel fhould be filled in fuch a manner with the
ether, as not to leave the fmallell portion of air
between the liquor and the bladder. Jt is now
placed under the recipient BCD of an air-pump,
of which the upper part B is fitted with a lea-
thern collar, through which palTes a wire £F,
having its point F very (harp ; and in the fame
receiver there is placed the barometer GH. The
whole being thus difpofed, let the recipient bo
exhaufted, and then, by pufhing down the wire
EF, a hole is made in the bladder : Immediate-
ly the ether begins to boil with great violence,
and is changed into an eVaftic aetiform fluid,
which 6Ils the receiver. If the quantity of etiier
be fufficient to leave a kw drops in the phial
after the evaporation is finilhed, the elaflic fluid
produced will fuftain the mercury in the baro-
meter attached to the air-pump, at eight or tcrv
inches in winter, and from twenty to tweirty-

premife here, tbu i[ is a very volatile and highly iriflim-
mablc li<lUor, hLyiitg & confidccatly fmaller fpeciiic gr^^
viry than waici'^tc^gyo) fjiiit ©^ y(JB<.f-rrJ^-

58

ELEMENTS

five in fummfer*. To render this experimei
more complete, we may introduce a fmall ther-
mometer into the phial A, containing the ether,
which will be found to defcend confiderably du-
ring the evaporation.

The only effeft produced in this experiment
li, the taking away the weight of the atmofphere,
which, in its ordinary ftale, prefles on the fur-
fece of the ether; and the effeifla refulting from
this removal evidently prove, that, in the ordi-
nary temperature of the earth, ether would al-
ways exift in an aeriform ftate, but for the prcf-
fure of the atmofphere, and that the change of
the ether from the liquid to the aeriform Hate
is accompanied by a confiderable diminution of
temperature ; becaufe, during the evaporation,
ft part of the caloric, which was before in a free
ftate, or at leaft in equilibriof in the furround-
ing bodies, combine? with the ether, and caufes
it to afliime the aSriform rtate, ■ : i

The fame experiment fuccecda with all eva-
"porftble

* It wonld havb b«en more l^tiifafiory If the Aulhoi<
bftd fpenRfld the degrees of the thn'moneter at wbicTr
tiiefe bogha of tlw inetcurj ia tbc-biroiA'ccef are pMl
duced. — T.

■\ 1 Oiould rather fuppofe, according to Mr Lavoijiet't'
own principles, that the evaporation is produced in confe-
qaeace of the equilibrium betwi-cn the Jrirpiilfive force of
the caloric contained in the cthei', and the refil^nce to
e^cpaniion exerted by the ntmorpheric prcirurc being rC-

ffcd.— T.

OF CHEMISTRY.

59

porable fluids, fiich as alkohol, water, and even

mercury ; with this difference, that the aimo-
fphere, formed in the receiver by aUtohol only,
fupports the attached barometer about one inch
in winter^ and about four or five inches in fum-
mer; that formed by water, in the fame fitua'*
tion, raifes tbe mercury only a few lines ; and
that produced by quiokfilver raifes it but a few
fraftions of a line^ There is therefore left fluid
evaporated from alkohol than from ether, lefs
from water than from alkohol, and flill lefs' from
mercury than from either ;■ confequently there
is lefe caloric employed, and Itfs cold produced^
which quadrates «xaiaiy withtht PefulM of thflfe
experiments. = " '

Another fpecics-of experiiMM-' proves vcry-e''
vidently, that the aeriform ftate is a modiBcatton
of bodies-dependent on tho degree- of tempera-
ture, and on the prefTure wbich thele bodies un-
dergoi In a Memoir read by Mr de la Place and-
myielf to the Academy in- §777, -which has not
been printed, we have ftiewn^ that> whenetherw
fubjeAedtoa prefiure equal to twenty-eight incht^
es*of the barometer, or about the medium-pref*
fure-of the atmofphere, it boils at the temperaldrt'
of about 104°, or 10.25* of the thermomctei^
Mr de Luc, who has made lirailar experiments
with fpirit of wine, finds it to boil at 132.75'' ■

IAndall the world knows that water boils at 212°.
Now, boiling being only the evaporation of a
liquid.

6o

ELEMENTS

ig from th^^

liquid, or the moment of its pafling f
fluid to the aeriform ftate, it is evident that, if
we keep ether continually at or above the tem-
perature of 106.25", and under the common
prelfure of the atmofphere, we fhall have it al-
ways in an elaftic aeriform Hate ; and that the
feme thing will happen with alkohoi when a-
bove 182.75°, ^"^ with water when above 212° ;
all which are perfedly conformable to the fol-
lowing experiment *.

I filled a large veflTel ABCD (Plate VII.
Fig. 15.) with water, at iio.ys", or 113° : I fup-
pofe the veflel tranfparent, that we may fee what
takes place in the experiment; and we can ea-
fily hold the hands in water at that temperature
without inconvenience. Into this veflel I plunged
fome narrow necked bottles F, G, filled with the
water and turned up, fo as to reft on their mouths
on the bottom of the veflel. Having next put
fome ether into a very fmall matrafs, with its
neck, a be, twice bent as in the plate, I plunged
this matrafs into the water, having its neck in-
ferted into the mouth of one of the bottles F.
Immediately on feeling the effedts of the heat,
communicated to it by the water in the veflel
ABCp, the ether began to boil, and the caloric,
ei^eripg into cotnbinatioa with it, changed it in-

• Vide Memoirs of the French Academy, flimo 1780,
p. 335— A.

OF CHEMISTRY. 6i

to an elaftic aeriform fluid, with which I filled
feveral bottles fucceffively, F, G, &c.

This is not the place to enter upon the exami-
nation of the nature and properties of this aeri-
form fluid, which is extremely inflammable ;
but, confining myfelf to the objeft at prefent in
view, without anticipating eircumflances, which-
I am not to fuppofe the reader to know, I (hall
only obferve, that the ether, from this experi-
ment, is almoft only capable of exifling in the
aeriform (late in our ufual temperatures ; for, if
the weight of our atinofphere was only equal to
between 20 and 24 inches of the barometer, in-
ficad of 18 inches, we ftiould never be able to
obtain ether in the liquid (late, at leaf! in Turn-
mer. The preparation of ether would confc-
quently be impofTible upon mountains of a mo-'
derate degree of elevation, as it would be con-
verted into gas immediately upon being prodo-
ced, unlefs wc employed recipients of extraor-
dinary ftrength, aflifted by refrigeration and
comprefTion. And, laftly, the temperature of ihe
blood being nearly that at which ether pafTes
from the liquid to the aeriform tlate, it muft eva-
porate in the prira« viae, and confequently it is
very probable that the medical properties of this
fluid depend chiefly upon its mechanical etfefl.

Thefe experiments fucceed better with nitrous-
ether, becaufe it evaporates in a lower tempera-
ture than fulphuric ether. It is more diflicult

6z

ELEMENTS

to obtain alkohol in the aeriform flate^becaufe,
as it requires a temperature of 182.750 to raife
it to vapour, the water of the bath muft be al-
mod boiling, and it U impolTiblc to plunge the
hands into it at that temperature.

It is evident that, if water were ufed in the
feft-flgoing experimeDt, ttwould be changed in-
to gas, when expofed-to a temperature fiiperior
tothat at which it boils : Although thoroughly
convinced of thi?,. Mr de la Place and mjfelf
judged it neceflary to confirm it by the follow-
ing direft experiment. We filled a glafs-jar, A,
(Plate VII. Fig. 5.)' with mercury, and placed
It, with its mouth downwards, in a diib, B, like-
wife filled with mercury, and introduced about
two drams of water into the jar, which rofe to
the lop of the mercury at CD ; we then plun-
ged the whole apparatus into an iron boiler,
EFGH, full of boiling fea-water of the tempe-
rature of 223.15", placed upon the furnace
GHIK. So foon as the water over the mercu-
ry reached the temperature of 212°, it began to
boil -f and inflead of only filling the fmall fpace
ACD, it was converted into an aeriform fluid,
which filled the whole jar; the mercury even
defcended below the furface of that in the dilh
B ; and the jar muft have been overturned, if it
had not been very thick and heavy, and fixed to
the dilh by means of iron-wire. luunediately
after withdrawing the apparatus frora the boil-;

OF CHEMISTRT.

63

I

^r, the vapour in the jar began to condcnfe, and
the mercury rofe to its former llation j but the
water returned again to the aeriform Itate ia a
few feconds after replacing the apparatus in the
boikr.

We have, thus a certain number of fubftan-
ces,^ which are convertible into elaftic aeriform
fluids, by degrees of temperature not much fu-
perior to that, of our atmofphere. We Ihall af-
terwards find that there are feveral others which
undergo the fame change in limilar circumflaa-
ccs, fuch as muriatic or marine acid, ammoniac
or volatile alkaii, the carbonic acid, or fixed air,
th^e fulphurous acid, &c. All thefe are perma<
nently elaftic in or about the mean temperature
of the atmofphere, and under its common pref-
fuve.

All thefe faQs, which could be eafily raulti-
pljed, if neceflary, give full right to affumc, ai a
general principle, that alraoft eva'y body in na-
ture is fufceptible of three feveral dates of«xift-
encc, foltd, liquid, and aeriform ; and that thefe
three Hates of exigence depend upon the quan-
tity of caloric combined with the body, Hence-
Ibrwards I fhall esprefs thefe elaftic aeriform
fluids by the generic terra ^a/; and in each fpe-
cies of gas I ihall diftinguiih between the calo-
ric, which io fome meafure ferves the purpofe of
ft folvent, and the fubflance, which, in combina-
tion with the caloric, forms the bafe of the gas.

To

64

ELEMENTS

To thefe bafcs of the dlfTercnt gafl
are hitherto but little knowa, we have been ob-
liged to aflign names ; Thefe ftiall be enumcra-
ted in Chap. IV. of this work, when I have pre-
vioufly given an account of the phenomena at-
tendant upon the heating and cooling of bodies,
and when I have eftabliftied precifc ideas con-
cerning the compolition of our atmofpherc.

We have already fhewn, that the particles of
every fubftance in nature exift in a certain ftate
of equilibrium, between that attraftion which
tends to unite and keep the particles together,
and the effefls of the caloric which tends to
feparate them. Hence, caloric not only fur-
rounds the particles of all bodies on every fide,
but fills up every interval which the particles
of bodies leave between each other. We may
form an idea of this, by fuppoling a velTel fill-
ed with fmait fpherical leaden bullets, among
which a quantity of fine fand is poured; this,
infinuating itfelf into the intervals between the
bullets, will fill up every void. The balls, in
this comparifon, are to the fand which furrounds
them fxaitly in the fame fituation as the par-
ticles of bodies are with refpedl to the caloric:
with this difference only, thai the balls are fop-
pofed to touch each other, whereas the particles
of bodies are not in contaA, being retained at
a fmall diftance from each other by the calo-

tf

or CHEMISTRr.

I
I

If, inftead of fpherical balls, we fubftiiute lb-
iid bodies of a hexahedral, oclohedral, or any
other regular figure, the capacity of the intervals
between them will be leiTened, and confcquently
will no longer contain the fame quantity of fand.
The fame thing takes place with refpciit to natu-
ral bodies ; the intervals left between their par-
ticles are not of equal capacity, but vary incon-
fequence of the diifercnt figures and magnitude
of their particles, and of the dillance at which
thefe particles are maintained, according to the
cxilling proportion between their inherent at-
traction, and the repulfive force exerted upon
them by the caloric.

In this manner we mud underiland the fol-
lowing expreffion, introduced by the EngJifh
philolbphers, who have given us the firll precife
ideas upon this fubjed; ibe capacity (if bodies
for eontaining the matter of heat. As comparifons
with fenflble objeds are of great ufc in aflifting
Mi to form diftinifl notions of abflraifl ideas, I
lh:i]l endeavour to illuftrate this, by inftancing
ilie phenomena which take place between water
and bodies which are wetted and penetrated by

kjt, with a few refledions.

fe If equal pieces of diflerent kinds of wood, fup.
pofe cubes of one foot each, be immerfed in
water, the fluid gradually inUnuates itfelf into
their pores, and the pieces of wood are aug-
mented both in Wi-'ight and magnitude : ilach
£ fpecies

66

ELEMENTS

fpecies of wood will imbibe a differeot quantity
of water ; the lighter and more porous woods
will admit a lam-rr, the compad and clofer
grained will admit a lefTer quantity ; for the
proportional quantities of water, imbibed by the
pieces, will depend upon the nature of the con-
ftituent particles of the wood, and upon the
greater or leffer affinity fubfifting between them
and water: Very reilnous wood, for inftance,
though it may be at the fame time very porous,
will admit but little water. We may therefore
fay, that diflferent kinds of wood poflefs differ-
ent capacities for receiving water ; and we may
even determine, by means of the augmentation
of their weights, what quantity of water they

OF CHEMISTR-A'.

fion very confiderable diverfities in the refults
of cxiicriments made upon thefe two fulpftaa-

CCS.

Having eflabliftied thefe clear and fimple pro-
pofitions, it will be very eafy to explain the ideas
■which ought to be affixed to the following ex-
preflions, which are by no means fynonymous,
but poflels each a ftrifl and determinate mcaa-
ing, as in the followifig definitions :

Free caloric^ is that which is not combined
in any manner with any other body. But, as
we live in a fyftem to the matter of which calo-
ric has a very flrong adhefion, we are never
able lo obtain it in the ftate of abfolute free-
dom.

Combined caloric, U that which is fixed in bo-
dies, by afBnity or elective attraction, fo as to
form part of the fubftance of the body, even
part of its iblidity.

By the expreffion Jpeclfie caloiU of bodies,
we underflad the refpective quantities of calo-
ric rcquifite for railing a number of bodies of
the fame weight to an equal degree of tempe-
rature. This proportional quantity of caloric
depends on the dilUnce between the conftitu-
ent particles of bodies, and their greater or lelTer
degrees of cohclion; and iliis diftance, or rather
the fpace or void rctuhing from it, is, as I have
^^ already obferved, cillcd ihe capacity of bodies for
^m tfontaining caloric.

I

I

I

ElKi

i

«8

ELEMENTS

'Heat, conltdered as a fenfation, or, in other
words, fenfible heat, is only the effeft produ-
ced upon our fentienc organs, by the motion or
pafTage of caloric, djfengaged from the fur-
ronnding bodies. In general, we receive im-
prtffibns only in confequence of motion, and it
might be eftablifhed as an axiom. That, with-
out MOTION, THERE IS NO SENSATION. This

general principle applies very accurately to the
{enfations of' heat and cold : When we touch a
cold body, the caloric, which always tends to
becomein equiHbfio in all bodies, pafles from
our hand into the body we touch, which gives
113 the feeling or fenfation of cold. The direft
contrary happens when we touch a warm body ;

I

OF CHEMISTRT.

69

I

change of place of the caloric in tliofe bodies, of
which the thermometer forms ooe part ; it only
indicates the portion of caloric received, with-
out being a meafure of the wiiole quantity dif-
engaged, dilplaced, orabforbed.

The molt fimple and moft exzSt method for
determining this latter point, is that defcrihed
by Mr de la Place, in the Memoirs of tlie Aca-
demy, for the year 1780, p. 364; a i'ummary
explanation of which will be found towards the
conclufion of this work. This method conlllts
in placing a body, or a combination of bodies,
from which caloric is difengaging. in the middle
of a hollow fphere of ice ; and the quantity of
ice melted becomes an exaift relative raeafiire of
tlie quantity of caloric difiSngaged. Itispofliblc,
by means of the apparatus which we have got
conllruited upon this plan, to determine, not as
has been pretended, the capacity of bodies for
containing hear, but the ratio of the increafe or
diminution of capacity produced by determi-
nate degrees of temperature- It is eafv, with
the fame apparatus, by varioufly combined ex-
periments, to determine the relative quantities
of caloric neceflary for converting folid fubftan-
ces into liquids, and liquids into elallic ai^rifom
fluids 1 and vice verfa, what quantity of calo-
ric efcapcs from elallic vapours in changing to
liquids, and what quantity efcapcs from liquids
during their converfion into folids. Perhaps when
£ J expernnenr-i

ELEMENTS

explremeots (ball have been made with fufficient
accuracy, we may one day be able lo determine
the proportional quantities of caloric neceflary
■for producing the leveral fpccies of gafles. I
fhall hereafter, in a feparale chapter, give an ac-
count of the principal refiihs of fuch experi-
ments as have been made upon this head.

It remains, before finilhing this article, to fay
a few words concerning the caufe of the elufti-
city of gaffes, and of liquids in the Hate of va-
pour. It is by no means difficult to perceive
that this elafticity depends upon that of caloric,
which feems to be the moll eminently elaftic
body in nature. Nothing is more readily con-
ceivable, than that one body fliould become
elaftic, by entering into combination with ano-
ther body poffeflcd of that quality. We muil
allow that this is only an explanation of elafti-
city, by an aflumption of elaliicity ; we thus
only remove the difficulty one Hep farther, and
the. reafon for caloric being elaftic, ftiU remains
unexplained. Elafticity in the abftraft is mere-
ly a fuppofable quality inherent to the particles
of bodies, by virtue of which they recede fronv
each other when forced together. This tcnden-
cy in the particles of caloric to feparate, takes
place even at conliderable diftances. We fttaI^
be fatishcd of this, when we coniider that air
is capable of undergoing great coraprclEon.
which fuppofca that its particles were previouf-
.'« •lijiijcru ly

OF CHEMISTRY. 71

I7 at a confideraUe diftance .from each other ;
for the power of approaching together certainly
fuppofes a previous diftance, at leaft equal to
the degree of approximation : Confequently;
thofe particles of the air, which are already con-
fiderably.diftant from each other, tend to fepa-
ratc ftiU &rther« If we produce Boyle's vacuurii
in a large receiver of aniair-piimp, the la!ft;por*
tion of ait which, remains extends itfeie.aniforni.
ly through the whole capacity of the veflel, how-
ever large, filling it completely, and prefling
every where againft its fides : We cannot ex-
plain this faA, without fuppofing that the par-
ticles make an effort to fepamte thcmfelves on
every fide ; and we arc quite ignorant at what
diftance, or in what degree of rarefadion, this
eflfort ceafes to adt.

In the above experiments a true repulfioii
takes place between the particles of elaftic
fluids ; at leaft, circumftances occur exadly as
if fuch a repulfion adlually exifted : and we have
a right to conclude, that the particles of caloric
mutually repel each other. When we are once
permitted to fuppofe this repelling force, the
theory of the formation of gafles, or aeriform
fluids, becomes perfedlly fimple j though we
muft, at the fame time, allow, that it is ex-
tremely difficult to form an accurate concep-
tion how this repulfive force ads upon very mi-

E 4 nute

72

ELEMENTS

nute particles placed at great diftancos from eacM
Other.

It 19, perhaps, more natural to fuppofe, that
the particles of caloric have a ftrongec mutual
attradion than tbofe of any other fubftaocc^
and that thefe latter particles are torn afundei
in confequence of this fuperior attradlion of the
particles of caloric, which forces them between
the particles of other bodies, that they may be
able to reunite with each other. We may ob'
ferve fomething analogous to this idea in the phe-
nomena which occur when a dry fponge is dipt
in water : This fponge fwells ; its paiticlcs fepa*
rate from each other ; end all its intervals are
filled by the water. It is evident, that the fponge,
in the at^^ of I'welling, has acquired a greater

OF CHEMISTRY. 73

dry. But we cannot certainly maintain, that
the introdudion of water between the particles
of the fponge has endowed them with a repul-
five power, which tends to feparate* them from
each other; on the contrary, the whole phe-
nomena are produced by means of attradive
powers : Thefe are, the gravity of the water,
and the power which it exerts on every fide,
in common with all other fluids ; The force of
attradion, which takes place between the parti-
cles of the water, caufing them to unite toge-
ther ; The mutual attraAion of the particles of
the fponge for each other ; and. The recipro-
cal attraftion which exifts between the particles
of the fponge and thofe of the water. It is
eafy to underftand, that the explanation of this
faft depends upon properly appretiating the in-
tenfity of, and cdnneftion between, thefe feve-
ral powers. It is probable, therefore, that the
feparation of the particles of bodies, occafioned
by caloric, depends in a fimilar manner upon
a certain combination of different attradive
powers, which in conformity with the imperfec-
tion of our knowledge, we endeavour to exprefs
by faying, that caloric communicates a power of
repulfion to the particles of bodies.

I CHAP.

ELEMENTS

General P^iews concerning the Formation and Corn'
pofition of our Almofpbere.

THESE views which I have taken of the far-
mation of eladic aeriform fluids or gaffes,
throw great light upon the original formation
of the atmofpheres of the planets, and parti-
cularly of that of our earth. We readily con-
ceive, that it niuft neceffarily conlift of a mix-
ture of the following fuhllances: Of all bodies
that are fufceptible of evaporation, or, more
ftriilly fpeaklng, which are capable of retain-
ing the ftate of aeriform elafticity in the tem-
perature of our atoiofphere, and under a preflure
equal to that of a column of twenty-eight inches
of quicklilver in the barometer ; and, of all fub-
ftances, whether liquid or folld, which are ca-
pable of being diflblved in this mixture of ditfe-
rent gaffes.

To fix our ideas more clearly refpedling this

fubjcfl, which has not been hitherto fuiEcient-

ly confidered, let us, for a moment, conceive

what change would take place in the various

fubftances

OF CHEMISTRY. 75

fubftances which compofe our earth, if its tem-
perature were fuddcnly altered. If, for inftance,
we were fuddenly tranfported to the region of
the planet Mercury, where probably the com-
mon temperature is much fuperior to that of
boiling water ; the water of oar world, and all
the other fluids which are fufceptible of the gaf-
feous ftate, at a temperature near to that of
boiling water, even quickfilver itfelf, would be-
come rarefied ; and all thefe fubftances, being
changed into permanently aeriform fluids or gaf-
fes, would become part of the new atmofphere.
Thef6 new fpecies of airs or gafles would mix
with thofe already exifting, and certain recipro-
cal decompofitions and nevv^ combinations would
take place, until fuch time as all the eledive at-
traftions or affinities fubfifting among all thefe
new and old gafleous fubftances had operated
fully y after which, the elementary principles
compofing thefe gafles, being faturated, would
remain at reft.

We muft attend to this, however, that, even
in the above hypothetical fituation, certain
bounds would occur to the evaporation of thefe
fubftandes, produced by means, of that very
evaporation itfelf : For as, in proportion to the
increafe of elaftic fluids, the preflure of the at-
mofphere would be augmented ; as every de-
gree of preflure tends, in fome meafure, to pre-
vent evaporatioa ; and as even the nioft eva-

porable

ELEMENTS

porable fluids can refift the operation of a very
high temperature without evaporating, if pre-
vented by a proportionally ftronger compreffioD,
water and all other liquids being able to fuflaia
a red heat in Fapin*3 digefter ; we mutt, admit,
that the new atmofphere would at la& acquire
fuch a degree of weight, that the water which
had not hitherto evaporated would ceafe to
boil, and, of confequence, would remain liquid.
Hence, even upon this fuppofition, as in all
ethers of the fame nature, the increafing gravity
of the atmofphere would find certain limits which
it could not exceed.

Wc might extend thefe reSeftions greatly
farther, and examine what change would be
produced in fuch littiations upon Itones, falts.

OF CHEMISTRY,

79

accompany igneous meteors induce me to be-
lieve that there exifts, in the upper parts of our
atmofphere, a ftratum of inflammable fluid, in
contad with thofe ilrata of air in which the phe-
aomena of the aurora borealis and other fiery ap-
pearaDces are produced.— -I mean hereafter to
purfue this fubje& in a feparate treatife.

CHAP.

ELEMENTS

CHAP. III.

jtnah^s of Atmojpberic Air, and Us Divifion into
two Etaftic Fluids ; tbt one jit for Kefpiration ;
tbe other incapable qf being rej^lred.

FROM what has been prcmifed, it appears,
that our atmofphere is compofed of a niix-
iprc of every fubftancc capable of retaining the
'gifleous or ui*riform ftaie in the common tempc-
rtnire«, and under tlie ufual degrees of preffiire
which ic experiences. Thefe fluids conftitute a
mafs, in Ibme meafure homogeneous, extending
from the furface of the earth to the greateft
height hitherto attained, of which the denfity
continually dccreafes in the inverfc ratio of the
l'ui»erincumbcnt weight. But, as 1 have before
obferved. it is pofliblc that this firft ftratum may ,
be rurmountcd by Icveral others conliAing of di£i^
fcrent fluids.

Our burincfs, in this place, is to endeavour
to determine, by experiments, the nature of
the elartic fluids which compofe the inferior ftra-
tum of air which we inhabit. Modern chemif-
try hs« made great advances in this refearch ;
and it will appear, by tbe following details, that
the onalylii of atmolphcrical air has been more
rigoroufly

OF CHEMISTRY.

8i

ligoroufly determined thaa that of .any other
fubftance of tbe clafs. ■ t ■, if

Chentiflry. ^tfords two general metbodft 0:f. de-
termining the conftituent principles of bodies,
the method of analyfis, and tliat of fynlhefis.
When, for inllance, by com billing water xvith
alkohol, we form tbe fpecies of liquor called, in
commercial language, brandy, or fpirit of wine,
we certainly have a right to conclude, thai
brandy, or fpirit of wine, is corapofed of alkohol
combined with water. We can procure the
fame refult by the analytical method ; and in
general It ought to be contidercd as a priiieiplQ
in chemical fcicnce, never to rcrt £atisfied with-
out both thcfc fpecies of proofs. We have this
advantage in the analylla of atmofpberjcal air ;
being able both to decompound it, and to form
it anew lu the mot\ fatiat'a&ory manner, i fhall,
however, at prefent confine myfeif to recouut
fuch esperioient) as are moH conclulive upon
this head ; and I may conHder mtiil of thefe as
my own, having either firft invented them, or
having repeated thofe of others, intended for
analyling atmofpheiical air, in perfedlly new
points of view.

I took a matraLs of about 36 cubical inches
capacity, having a long neck of fix or fcvcn lines
internal diameter, and having bent tbe neck, as

I in Plate IV. Tig. 2. B C £) E, to allow of its be-

I

ELEMENTS

ing placed in the furnace MMNN, in fuch i
manner that the extremity of its neck E might
be inferted under a bell-glafs F G, placed in a
trtHtgh ofquickfilver R R S S ; I introduced four
onnces of pure mercury into the matrafs, and,
by means ofafyphon,exhauftedthe air in the re-
ceiver F G, fo as to raife the quickfilver to L L,
and 1 carefully marked the height at which ic
ftood, by parting on a flip of paper. Having ac-
ciffately noted the height of the thermomctcD
and barometer, I lighted a fire in the furnace
MMNN, which I kept up almoft continually
during twelve days, fo as to keep the quickfilver
always very near its boiling point. Nothing re-
markable took place during the firft day : The
mercury, thojj^h not boiling, was continually
evaporating^ and covered the interior furface of
the veflel with fmall drops, which gradually aug-
menting to a fufficient fize, fell back into the
mafs at the bottom of the veflel. On the fccond
day, fmall red particles began to appear on the
furface of the mercury, thel'e, during the four or
five following days, gradually iijcreafed in fize
and number, after which theyccafed to increafc
in either rcfpeift/ At the end of twelve days, fee-
ing that the calcination of the mercury did not
iitall increafc, I extinguilhed the fire, and allow-
ed the ceQels to cool. The bulk of atr in the
body and neckxf the matrafs, and in the bell-
|Iafs,

OF OHEMISTRY.

.83

■glafs, reduced to a medium of 28 inches of the
barometer and 54.5* of the thermometer, at the
commencement of the experiment was about 50
cubical inches. At the end of the experiment
the remaining airj reduced to the fame medium
preifure and temperature, was only between 42
and 43 cubical inches ; conf^uently it bad lolt
about 5" of its bulk. Afterwards, having col-
lefled all the red particles, formed during the
experiment, from the running mercury in which
they floated, 1 found thefe to amount to 45
grains. ; ,

I WRG obliged to repeat this experiinejit fevf-
ral times, as it is difficult, in one experiment,
both to preferve the whole air upon which we
operate, and to coHe6l the whole of the red pax-
1 tides, or calx of mercury, which is formed du-
I :ring the calcination. It will oftea happen in
-the ftquel, that I Ihall, in this manner, give in
one detail, the refults of two or three experi-
ments of the fame nature.
The air which remained after the calcination *
I .of the mercury in this experiment, and which
-was reduced to {- of its former bulk, was no
longer fit either for refpiration or for combuf-
tioo ; animals being introduced into it were fuf-
focated in a few feconds, and when 9 taper was
plunged into it, it was extinguilhcd, as if it had

I been immerfed in water.
f .%. F z In

b

E'Dfe-Mt-JJ-'T-S"

' In the next plact,' I took the 45 grains of red
matter formed daring this experiment, which I
put into a' ftnall glit6 retort, having a proper
ap'l^iSHt^ fof- receiving fuch liquid, or gafleous
prodntft, ■as might be estrafted : Having applied
a-'-ftre TO the retort in the furnace, I obferved
that^ in praportion as the red matter became
hfeatetii tht iotenfity of its colour augmented.
Wheh the retort was alnioft red hot, the red
mattCL- began gradually to decreafe in bulk, and
ih a few minirtes after it difappeared altogether -y
at the fume time 41^ grains of running rewrcury
WWe'ctfTW^'d'in the recipiem, and 7 or 8 cu-
tncaTlnchrs of chOic fluid-, greatly more capa-
Me of fapjibrting both refpiration and combuf-
tibn than atmofphetical air, werfc cotlccSled in
tht bcH.'glafs.

■' Apart o^f this air being put into a glafs tube
•<^ about ^ci inch diameter, fliewed the foUowing
properties: A taper bnrtied in it with a daz-
7.1ing fplendour, and charcoal, inftead of con-
"fumillg (jfuietly, as it docs in common air, burnt
■with a tiaifle, attended rtitbfi decrepitating noifc,
liVe phofphbrus, ami threw out fuch a bril-
liant light Vhat the ey« conld hardly endure it.
■f his fpecics of air was difcovered almoft at the
fame tiratf by Dr Prieftley, Mr Scheele, and
riiyfeltt Dr Prieftley gave it the name of de-
phlogifiicated air i Mr Scheele called it empyreal
air : at firft I named it bisl-fy refpirahle air, to
which

OF CH^BflSTRy. 85

which, has Hace been ful^ituted the .term of
vital air. We ihalL prefently fee. wJtiat.wei)ukht
to think of thefe dcnoin^iatiojqs. . .v,„,. .. .,^-.
Ii;i xcfl^<Jling, upon the circuin^;;i9es of tjiis
experiment, we refidilv JierPfiive .; th^t the iner-
cufy^TrurTng ijts calcination, ' abforbs the ./aiu-
brious and refpirable.p^,ctf the a[rj^jjr^ to; fpeak

th^t.^he lemainixig air 18 a fpeoies ,9f »^[|bi^^,
incapable of f^pporting. combuflion 9x,-,rg|pifa;
tion ; and, confequently, that atmofpl^f n^ air i$
compofed of two elaflic: fluids of 4i^9f5^t and
oppofite qualities. As ^ proofj of this important
truth, if we recombine thefe two.elalUc fluidSf
which we have feparatdy obtained in the above
experiment, viz. the 42 cubical inches of mephi-
tis, with the 8 cubic^ inches of highly: refpirable
air, we reproduce an air precifjply iimilar .to that
of the atmofphere, and poflTefling pearly tUe fame
power of fupporting combuftion and .refpiration,
and of contributing to the calcination of nieti^*
Although this experipient furniflics us wjtl^
a very limple means of , obtaining; the^lwq PfA^-
cipal elaftic fluids which compofe . pifT -atjg;i9*
fphere, feparate from each other, yet >t , does n;^
give- q^, an exad idea of the proportioujui which
thefe two enter into ; its compofi^Qu : ^p^ the
attradion of mercury to the, , refjnf a^le^gart of
the air, or rather to its bafc, is npt f M^cid^tly
^rong to overcome aU^ie circumJftianqe^ wb^ch

. F 3 oppofil

Elements

oppofc this union. Thefe obftaclcs arc the l
tual adhefion of tlie two conrtituent parts of
the atmofpliere for each other, and the elcftive
attraflion which unites the bafe of vital air with
caloric; in confequence of thefe, when the cal-
cination ends, or is at leaft carried as far as is
poffible in a determinate quantity of atniofphc-
riC air, there flill remains a portion of refpirahle
air United to the mephitis, which the mercury
cannot fcparate. I (hall afterwards fhew, that
at leaft in our climate, the atmofpheric air is
compofecl of refpirablc and mephitic airs, in
the proportion of 27 and 73 ; and I fhall then
difcufs the ciufes of the uncertainty which ftill
cxifts with refpefl to the exadnefs of that pro-
po'rtion.

--'■feince, during the calcination of mercury, air
4s 'decoinpofed, and the bafe of its refpirable
part is fixed and combined with the mercury,
it fttlibws, from the principles already eftablifh-
ed, that caloric and light murt be difengaged
iliiring the procefa. Bat the two following
ctmfes prcvehl us firom being fenfible of this
tfllcirtg Wacc ; as the calcination lafts during fe-
deral days, the difengageraent of caloric and
light, fpTCad but in a confidcrable fpaceof time,
becomes extremely fmall for each particular
■moment of the time, fo as not to be percep-
'tiblej-and, the operation being carried on by
"inedilis of fire in a furnace, the heat produced

OF CHEMISTRY.

S?

I

^jy the calcination itfelf becomes confounded
with that proceeding from the fursacel I
might add, that the refpirable part of the air, or
rather its bafe, in entering into combination
with the mercury, does not part with all thtf
caloric which it contained, but ftill retains it
part of it in the new compound : but the i]f-
cuffion of this point, and its prooft from ex-
periment, do not belong t-o this part of out
fubjeft.

It is, howerer, cafy to render this difengage-
ment of caloric and light evident to tlie fenfes,
by cBufing the decompofition of air to take
plsce in a moie rapid manner j and for this pur-
pose, iron is excellently adapted, as it (pGlTtires
II much ftrooger affinity for the bafe of refpira-
ble air than mercury. The ibllo wing elegant ex-
periment of Mr Ingenhoui, upon the combuf-
-tion of iron, is well known. Take a piece of
fine iron wire, twilled into a fpiral, BC, Plate
IV. Fig. 17.,; fix one of its extremities B into
the cork A, adapted to the neck of the bottle
DEFG, and fix to the other extremity of the
wire C, a fmaU morfel of tinder. Matters hf-
ing thus pcepared, fiU the bottle liEFG with
nir deptived of its mephitic part ; then light
the tinder, and intioducc it quickly, with the
■wire upon which it is fixed, into the bottle,
which you flop up with the cork A, as is iliown
^n the figure 17. Plate IV. The inftant the
F4 lighted

n

.%:tX MI;E-!»T S-<,

Hghted'tin^ec ,ccpie$t.:ii4p.;C0Dtai^ ijvi^, the. y;i-
pil air, it begin;;'|:o bupn .w^ gre3t f^Jten^tj.^
%Iidi;.c(>i»fnMnj««ing tftc. jipflapinntion. t^-Mi^
iroR^witffejtJjJcewife j^^iw§ fire and Iji^nsfapid^y,
thrp^'ing; iQUt t^filliant fparks ;. thefe fajl.ta the
feottftinpf tftipiVfiflfl in ijopoded globules, which
tsepiiai? jfel*c]tLtft 9pfllii»g,;bMt fetaia a degfce
of met»U;ic, ifp^idj^fij : ■ :7be ;irpn ^hus b^l:nt is
iH,oj-e.;^r}«l^ ¥Kfp ^afl glgTs, is eafily i;educe4
into powder, and is ftill attradable by thr mag-
aet„tbo^gh not fo.^oi^^^j^aB it was tjefpre
co^tbuftion. Ml Mk irrgoi^puz h^ iieithei e^.
Rin)fie;d tt^e change: priced on the iron, nor
upon (be air hy thtF.QpKratign, ,1 have repeated
tli.e experiment:. uii4«i;. different circiyull^n^ies,
ill an gpfiarattrt adaptgd to aoCwer my pprupu-

OF CHEMISTRY.

I

bxed a froall iiior(^^ of tinder, to which was
added aVout the lb(.teenth pan of a grain of
phofphoEUs ; and, by raifing the bell-glafs a
little, the chioa cup, with its contents, were in-
troduced into the pure air. I know that, by this
means, Ibmc common air muH mix with the
pure air in the glafs; but this, when it is done
dexteroufly, is lb very trifling, as not to injure
the fuccefs of the experiment. This being done,
a part of the air was fbcked out from the bell-
glafs, by means of a fyphon GHI, fo as to raife
the mercury within the glafs to EF ; and, to
prevent the mercury from getting into the fy-
phon, a fmall piece of paper was twifled round
its extremity. In fucking out the air, if the
motion of the lungs only b? ufed, we cannot
make the mercury rife above an inch or an inch
and a half > but, by properly uUng the muA:les
of the mouth, we can, without difficulty, caufe
it to rife fix or feven inches.
, I next took an iron wire, MN, Plate IV.
f igf i6. properly bent for the purpofe, and ma-
king it red hot in the fire, paffed it through the
mercury into the receiver, and brought it in
coniacl with the fmall piece of phofphorus at-
tached to the tinder. The phofphorus inftant-
ly took fire, which communicated to the tin-
der, and from that to the iron. When the
, pieces have been proper!;, arranged, the whole
iron burns, even to the laft particle, throwing

out

5D ELEMENTS

out a white brilliant light fimilar to that of Ch!
nefe fireworks. The grfcat fieat produced by this
combuftion melts the iron into round globules
of different fizes, moft of which fall into the
China cup ; but fome are thrown out of it, and
fwim on the furface of the mercury. At the
beginning of the combuftion, there is a flight
augmentation in the volume of the air in the
bell-glafs, from the dilatation caufed by th^
heat; but, prefently afterwards, a rapid dimi-
nution of the air takes place, and the mercury
rifes in the glafs, infomuch that, when the quan-
tity of iron is fufficient, and the air operated
upon is %-ery pure, alraofl the whole air employ,
ed is abforbed.

It is proper to remark in this place, that, un-
Icfs in making experiments for the purpofe of
difcovery, it is better to be contented with burn-
ing a moderate quantity of iron ; for, when
this expeiiment is pulhcd too far, fo as to ab-
forb much of the air, the cup D, which floats
upon the quickfilver, approaches too near the
"bottom of the bell-glafs ; and the great heat
produced, which is followed by a very fuddea
cooling, occafioned by the contaift of the cold
mercury, is apt to break the glafs: In which
■fcafe, the fudden fall of the column of mercury,
f "Hrtiich happens the moment the Icaft flaw is
I ■'pi'oduced in the glafs, caufcs fuch a wave, as
, "^throws a great part of tiic quickfilver from the

OF CHEMISTRY.

91

bafon. To avoid this inconvenience, and tp en-
fure fuccefs to the experiment, one dram and a
half of iron is fufiicient to burn in a bell-glafs,
which holds about eight pints of air. The glafs
ought likewife to be ftrong, that it may be able
CO bear the weight of the column of mercury
which it has to fupport.

By this experiment, it is not podible to de-
termine, at one time, both the additional weight
acquired by the iron and the changes which
have taken place in the air. If it is wiflicd to af-
certain what additional weight has been gained
by the iron, and the proportion between that
and the air abforbed, we muft carefully mark
upon the bell-glafs, with a diamond, the height
of the mercury, both before and after the ex-
periment. After this, the fyphon, GH, PI. IV.
^ig. 3. guarded, as before, with a bit of paper,
to prevent its filling with racrcpry, is to be in-
troduced under the bell-glafs, having the thumb
placed upon the extremity, G, of the (yphon, to
regulate the paQiige of the air; and by this
mcam the air is gradually admitted, fo as to let
the mercury fall to its level. This being done,
tin: bell.glafs is to be carefully removed, the
globules of melted iron containqd in the cup,
and thofe which have been fcattered about, and
fwim upon the mercury, are to be accurately
fiollecied, and the whole is to be weighed. The
iron will be found in that flate called wrdr/io/
''•"'■ ethiopt

p»

ELE M E.N T^

etbiojfj bj the cild cbemifls. poQeflUip ji.degrse of
jnietejlic brilliancy, vfirjr &i»b)e, and rei^Uy jp-
ducibls isto powder, iii)dcr th« hummer, gr with
a peftle »nd mortar, ift^e experiment has fuc-
fzeedfd well, jTropi lop gr^ns ofkon will be ob-
twned 135 or 136 gr^ns qf ethiops^ vhich U ^
augmentation of 35 per ceitt.

If 9II the attention has been .p^d to this ex-
pcrii^ent which it deferres, the air. 'will be found
diminilhed in weight, eyaftly equal (o what the
iron has gained. (laving therefoiie burnt loo
graios of ivon, which has acquired an addition-
al weight of 35 grains, the diminution of air
will be found txz€t\y 70 cubical incheB j and
it will be Ihewn, in the fequel, that the weight
of vital air is very near half a grain for each

r

H mill)
H Afte
^P have

I

OF CHEMISTRY. 93

inuft operate in a fomewhat different manner.
After the combuftion is finiflied, and the veffels
have cooled, we firft lake out the cup, and the
burnt iroii, hy introducing the hand thronj*h the
quickfilver, under the bell-glafs ; we next intro-
duce fome folution of poiafli, or cauftic alkali, or
of the fulphuretoFpoiafh, or fuch other fubftan-
CCS as are judged proper for examining their ac-
tion upon the reiiduum of air. I fliall, in thefe-
quel, give an account of thefe methods of analy-
ling air, when I have explained the nature of
ihefe different fubftances, which are only here in
a maiiaer incldently mentioned. After this esa-
minalioB, fo much water muft be let into the
glafs as will difplace the quicklilver, and then,
by means of a fliallow dilh placed below the bell-
glafs, il is to be removed into the common water
pneumatP- chemical apparatus*, where the mr
remaining may he examined at large, and with
great facility.

When very foft and very piire iron has been
employed in this experiment, and, when the
combuftion has been performed in the pureft re-
fpirable or vital air, free from admixture of the
noxious or mcphitic part, the air which remains
after

* For a particulsir defcnptidn of thii spparUtis, and
the manner of nfing it, and of tnaiiy oiber proceflcs, with
the inftrunicnts fitted for cairjing-iUem on, fcc rhe third

»

. put of thii V

oiccc the ci^mbuilioD will be found as pure as (t
wti* b«wfc : But it is difficult to find iron ea-
tirelv dw: trom_ a iinall portion of charry mat-
tc£, wJkich is chiefly Abundant in fteeli and it
i» Ukewite exceedingly di$cult to procure pure
air perfcdiy free, from fome admixture of me-
lius, witb which it is almoft always conta-
ounated : That fpecies of nojLious air does not,
in the fraalleft degree, diftiirb'the rcfult of the
experiment, as it is always found at the end
exactly in the fjvne quantity as at the begin-
ning.

I mentioned before, that We have two ways
of determining the conftituent parts of atmo-
fpheric air, the joaethod of analyfis, ^ni that by

OF CHEMISTST.

93

I
I
I

I

And, if we take 73 parts, by weight, of this
claftic fluid, and mix it with 27 parts of highly
refpirable air, procured from calcined mercury,
we fhali form an elaftic fluid precifely fimilac
to atmofpheric air in ail its properties.

There are many other methods of feparating
the refpirable from the noxious part of the at-
mofpheric air, which cannot be taken notice of
in this place, without aasicipating information,
which properly belongs to the fubfequcnt chap-
ters. The experiments already adduced may
fuffice for an elementary treatife ; and, in mat-
ters of this nature, the choice of our evidences
is of far greater confequence than their num-
ber.

1 {hall clofe this article, by pointing out the
property poflcffed by atmofpheric air, and all
the known gaffes, of diffolving water ; whidi
circumflance it is of great confequence to attend
to in all experiments of this nature. Mr Sauf-
furc found, by experiment, that a cubical foot
of atmofpheric air is capable of holding 12 grains
of water in folution *. Other gaffes, as the car-
bonic acid, appear capable of diffolving a great-
er quantity ; but cxpcriraems are ftill wanting

* It li evident tliat the (juuntiiy of water held in folti-
lion, by dctcrminBteqiiantilies of the different gafles, mud
vary according 10 the degrcia of itniptrBlurc and pielTure,

L

g6 ELEMX.N'TS

by which to determine their .£tvenl pntpor-
tions. This water, held in.fslutaon by gafles,
giTcs riie to particular phenomena, Which re-
quire great atteiDtion, in many cxperimeDts* and
which has frequently proved the fourc^ of great
errors to chcniifti ja dctennioing the refults of
theit CKperimenti; : .. : i

OF CHEMISTRY.

CHAP. IV.

Nomenchture of ibe froeral CmJlUitent Parts of
Atmojpberic Air.

I

HITHERTO I have been obliged to make
ufe of circumlocution, to exprcfs the na-
ture of the feveral fubftances which conftilute our
2tmofphere, having proviliooally ufed the tenns
of refpirabUf and noxious, or non-rej^irablc, parts
of the air. But the iuveftigations I mean to
undertake, require a more direct mode of ex-
preffion; and, having now endeavoured to give
limple and difiin£l ideas of the dilTerent fub-
ftances which enter into the compofition of the
atmofphere, I /hall henceforth exprcfs thefe
ideas by words equally limple.

The temperature of our earth being very
near to that at which water becomes folid, and
at which reciprocally it changes from foUd to
Quid ; and as this phenomenon takes place fre^
quenily under our obfervation, it has very na-
uirally followed, that, in the languages of at
leaft every climate fubjetfl to any degree of win-
ter, a terra has been ufed for fignifying water in
the (late of folidity, or when deprived of its ca-
G loiic.

EI. £M i: K T S

Tbe &ine piecifion has not been found
fcefikry with refped to water reduced to the
late of vspour by an additional quantity of calo-
Thofe perfonf wlj^ ^ouot make a particu-
lar ftudy of objeds of this kind, arc ftill ignorant
that water, when in a. temperature only a little
■bdre the bdiliAg^ heat; is twanged IdtO ftn' (Baltic
aerifonn fluid, fufceptible, like all other gafies,
of being received and contained in velTcls, and of
preferving its gafleous form fo long as it remains
«t tbe ter&perature of aiaf, aAdUndtriai^ef^
fare not cxceedii^ iS UKthse of ihcmBicuiiial -ba-
nunctcr.. A&^thitphenomcma has not been ve-
ry gttieially obfemd, no language fast nfedi a
partkular term for «Kprcffiiig water iathisiUiK^}
and the lame thing occurs with all fluids, ajld

I

OF CHEMISTRY.

S9j

vP

I
I

We h&ve not pretended to make an^ altera-
tion upon fuch terms as are landiSed by ancien
cuftom ; and, therefore, continue to ufe the won
water and ice in their common acceptation. W(
likewifc retain the word air, to exprefs that col-
ledion of elaftlc fluids whicli compofes our at-
mofpherti : But we hare not thought it necef-
fary to preferve the fame refped for modern
terms, adopted by the latter philofophers, having
con^dered ourfelves as at liberty to rejefl fuch
as appeared liable to give erroneous ideas of the
fubltances they are meant to exprefs, and cither
to fubftitute new terms, or to employ the old
ones, after having modified them in fuch a man-
ner as to convey more determinate ideas. New
lyords, when neccffary, have been borrowed
chiefly from the Greek language, in fuch a man-
ner as to make their etymology convey fome idea
of what was meant to be reptefenled by them ;
and we \have always endeavoured to make thcfc
fliort, and of fuch a form as to admit of being
changed ii)fo adjedives and verbs. •

Following thefe principles, we have, after
the example of Mr Macquer, retained the term
f a/, employed by Vanhclmont ; having arrang-
ed the numerous clafs of elaflic aeriform fluids
under that name, excepting only almofpheric
air. Gai, therefore, in our nomenclature, be-
comes s generic term, exprefling the fullcll de-
of faturation in any body with caloric ; be-
G 2 ing,

^■fOO

.'ELEMENT &.

Wing, in fad, a' term expteffive of a .mode of ex-
Jftence. To diftinguifh the fpecies of- gas, we
Kmploj a fecond tenii derived from the name
^f the bafe, which, faturated wldi caloric^ forms
each particular gas. ThUB^ we name ttattr corn-
bined to faturation with caloric, lb as to fonu an
elaftic fluid, aqueout gas ; ether dombioed in
the fame manner, rffr^fjtif«rv the comlwiation
ofaUcohol with caloric, \xcomk:& aUtobi^c gat }
and, following the lame principles, we have mu-
riatic acid gas, ammoniacai gas, aod fo on of eve-
ry fubftance fulceptible of being combined>witb
caloric, in fuch a manner* as to aflUme the gaf-
feous or elaftic aeriform ftate.

We have already feen, that the atmnfpheric

OF CHEMISTRt.

I

name of oxygen, from e£ut acidum, anj ydvsfia/,
g'ignor, becaufe one of the moft general proper-
lies of this bafe is to forlri acids, by combining
with many difTercnt fiibftances. The unioii of
this bafe with caloric, which is the faiiie WilH
what was formerly named pure, or vital, or bigb'
If refpirahle air, we no'tt' call oxygen gai. The
weight of this gas, at the temperature of 54.;6",
and under a preffiire ecjual to 23 inches of the
bai-ometer, is half a grain for each cubical inch
nearly, or one ounce and a half to eacli cubical

foot. I

The chemical properties of the' tios^oiis por-
tion of atmofpheric air being hitherto but litrlc
known, we have been fatisficd to derive the name
of its bafe from its known quality of killing
fuch animals aa are forced to breathe it, giving
it the name of azot, from the Greek privitive
particle » and f»«i, i-ita; hence the nam'e' of
the noxious part of atmofpheric air is atotie
gas. The weight of this, in the fame teAipera-
ture, and under the fame prelTure, is i oz. 2
dramt and 48 jrj. to the cubical foot, or O-4444
of a grain to the cubical inch. Wc cannot
deny that this name appears fomewhat extra-
ordinary ; but this mull be the cafe with all
new terras, which cannot be expelled to be-
come familiar until they have been Ibrae time
in ufe. We long endeavoured to find a more
proper defignation without fuccefs ■. It was at
G 3 fira

1^2 t hZ M EN T S

firll propofetl to call it alAalije/t gas, as, from
the experiraeiits of Mr BerthoUet, it appears to
enter into the compofition of ammoniac, or vo-
-Jatile alkali ; but then, we have as yet no proof
of its making one of the cpjoftituent elements of
the other allcalies ; befides, it is proved to form
a part of the nitric acid, which gives as good
reafon to have it called nicrigen. Fpr thefe rea-
fons, finding it neceffary to reject any name up-
on fyfteraatic principles, we have confidered that
wc run no rife of miftake, in adopting the terms
of (720/, and azotic gas, which only exprefs a
matter of fadl, or that property which it pof-
fe0eB, of depriving fuch animals as breathe it of
their lives.

I fliould anticipate fubjeds more properly re-
fcrved for the fubfequcnt chapters, were I in
this place to enter upon the nomenclature of the
feveral fpecies of gafles : It is fui^cient, in this
part of tlie work, to eftablini the principles up-
on which their denominations arc founded. The
principal merit of the nomenclature we have
adopted is, that, when once the liraple elemen-
tary lubilance is diftinguiflied by an appropriate
term, the names of all lis compounds derive rea-
dily, and neceflarily, from this firft denomi-
nation.

CHAP.

OF CHEMISTRY* toj-

'■-- ■ .-' CHA'C-'-V.

r-

Of tbt DeeimpoJ&ion 'of 'Okygen Gas fy HuMut;
PboMotiis^' and CM^n—Hnd of tht- Ittfma*'

principle, Wl^icli oug]ft never io be deviated
from, th^t they be fimplijied as much as pof-
fible, an^ that every cifcumftance capable of
rendering their refults complicated be carefully
removed. Wherefore, in the experiments which
form tl^e objeflt of thi,s chapter, I have never
employed atmofpherlc a^r, Tvhich is not a fimple
fubftahqef It is true, that the axotic ^as^ which
forms k part of its mixture, appears to be mere-
ly pailfive during combhflion and calcination y
but, befides that it retards thefe operations very
conifiderably, we are not certain but it may even
alter their refults in fome circumftances ; for
which reafon, I have thought it neceflary to re-
move even this poflible caufe of doubt, by ma-
king ufe only of pure oxygen gas in the fol-
lowing experiments, which (hew the efFefts pro-
duced by combuftion in that gas. I ihall ad-
vert to fuch differences as take place in the re-
fults of thefe, when the oxygen gas, or pure

G 4 vital

£..!>£ M;£N:T S

vital air, is iiiix.ed, in different proportions, with
azotic gas.

Having fiUed a beU-glafs A, PL IV. fig. 3. of
between five and fix j^qU ine^fure, with oxy-
gen gas, I removed it from the water-trougb,
where , it was filled^, ifitoi the- quickfilver Ijutb^
by means of a ihallow,g4af»-,diih flipped under-
neath, and having dried tt^e^^e|^cuiy, I introdu-
ced 61^ grains of Kunkel's phofphorus in two
little China cups, lik^ t^t reprefented at D^
fig. 3. under, the glaJTs /L * Ybat I miglitttt 'fir«(
to each of the portions oT'pi^ofphonuibpiiiately,.
and to prevent the oiie Som catching ^re from
the other, one of the difhes was covered with a
flat piece of glafs. I next raifed tb6 quick-

OF CHEMISTRY.

•OS

r

^H fide of the glafs becanae covered with light white
^H flakes of concrete phofophoric acid.
^B At the beginning of the experiment, the
quantity of oxygen gas, reduced, as before di-,
reded, to a common (landard of thcrmometrical
temperature and barometrical preffure, amount-
ed to 162 cubical inches ; and, after the com-
boftion was finiflied, only 23- cubical inches,
likewife reduced to the ftandard, remained; fb
that the quantity of oxygen gas abforbed during'
the combuilion was 158^ cubical inches, equal

• to 69.375 grain*.
A part of the: phofphorus remained uncon-
fumed in the bottom of the cups, wliich, being
waftied on purpofe to feparate the acid, weigh-
ed about 16-^ grains ', fo that about 45 grains of
■ phofphorus had been confumed : But, as it is
hardly poflible to avoid an error of one or two
grains, I leave the number fo far qualified.
Hence, as nearly 45 grains of phofphorus had»
in this experiment, united with 69.375 grains
of oxygen, aad as no gravitating matter could
have cfcaped through the gkfs, we have a right
to conclude, that the weight of the fubtlance re-
fulting from the combuftion in form of white
flakes, mull equal that of the phofphorus and
oxygen employed, which amounts to 114.375
grains. And we Ihall prefently find, that theftt
flakes conniled entirely of a folid or concrete
acid. When we reduce thcfe weights to hun-.
dredth

ELZMEN TS

!a.icvS be iboad that too p&m 6f-
:>ac±aaans a^aiR 154 parts of axjgea for &. .
zatmioa, ioi ate tins conbLoatioii will produce
2f;« 3100 « o.-«KRiie pba^hmiD and, iq fom

jc «iUK deecT iUbcs.

TteK cxpaisaeot pzores. m die noft convin-
CU19 atMnrr,th«,ttm cenain dt^me of tmi^ieiJ -
raoMk QixTSCB poflcfics a Avoiger eledWe at-
em^Nik ar sAnitr, tat fbo^horns than for c»- '
Ikk-: and diat, in confequence o]?tbivtfae phof-
yAuns jCirafts tlw bale of oxygui gu from the
oikeic. vhich. bang fct free, fj»«kd3 itfelf over
tl* nntxuidtnf; bodks. Bat, tbougb tiiis ex-
?Knc»tttt be lb te perfeAly conclttfive, it is not
t^JNficwKiT nl^lf«us; lor, ki At apparatus de-

OF CHEMISTRY.

107

>

I

iloppcr, I introduced the fupportBC, furmount-
ed by the China cup D, containing 150 grt. of
phofphorus; the ftopper was then fitted to the
opening of the balloon, luted with fat lute, and
covered with flips of linen fpread with quicklime
and white of eggs. When the lute was perfetfl-
\y dry, llie weight of the whole apparatus wa-s
determined to w^ithin a grain, or a giarn ant} R
half. I next exhaufted the balloon, by m«erM
of an air-pump applied to the tube ilxx, sod
then introduced oxygen gas by means of'ilK
tube yyy, which bus a ftop-cock adapted to it.
This kind of experiment ia moft readily and
mofl exadly performed by means of tiic hydros
pneumatic machine defcribed by Mr Meufoirr
and myfelf in the Memoirs of the Academy for
1,783, P'^'i^t ^n4 explained in the letter part
of this work, with I'everal imporcnnt atldition^
and corret^ions fince made to it by Mr Metii-
nier. Withtbis iuftrument, *ve can leadily sfr
certain, in the moft exaift manner, both the
quantity of oxygen gas introduced into the bal-
loon, and the quantity coufumed dnring tlic
courfe of the exi>eriment..

When alt things were properly difpofed, I fet
fire to the phofphorus with a burning-glals :
The combuftion was estremely rapid, accompa-
nied with a bright flame, and much heat : As
the operation went on, large quantities of white
flakes gradually attached tliemfelvcs to the in-
ner

■ ELEMENTS

ner furface of the balloon, until at Uft it't^as
rendered quite opake. The quantity of -tfaefe
fialces at the end became fo- abundant,- tha^
though ftcfli oxygen gas was coAtinuallj fup-
plied, which ought to have fuppoit^ the com-
buftion, the phofphorus became eztinguifhed.
Having allowed the apparatas to coolcompiete^
I7. 1 firft afi»Ttained the quantity of oxygen gas
employed, uid- weighed the balloon accurately,
before it was 'opened. I next wEilhed, dried,
and weighed the foaall quantity of pho^horus
remaining in the cup, on purpofe to determine
the whole quantity of pbofpbairus confumed m
Ae experiment ; this reOdnum of the phofphb>-
nu was of a yellow ochrey colour. It is eri-

I

I

OF CHEMISTRY.

top

I

determinable a "priori. If the oxygen gas cm-
ployed ' be pure, the refiduum after combuftion
is as pure as the gas employed : This proves
that nothing efcapes from the phofphorus, ca-
pable of altering the purity of the oxygen gas,
and that the only aftion of the phofphorus is to
feparate the oxygen from the caloric, with which
it was before united.

I mentioned above, that when any combuftl-
tle body is burnt in a hollow fphere of ice, or
in an apparatus properly conftruded upon that
principle, the quantity of ice melted during the
combuftion is an cxadl meafure of the quantity
of caloric difengaged. On this Tubjeit the me-
moir given to the academy by M. de la Place and
myfelf. A". 1780, p. 355, may be confulted.
Having fubmitted the combuftion of phofphorus
to this trial, we found that one pound of phof-
phorus melted a litde more than ico pounds of
ice during its combuftion.

The combuftion of phofphorus fucceeds equal-
ly well in atmofpheric air as in oxygen gas, with
this difference, that the combuftion is vaftly flow-
CTi.jfaeing retarded by the large proportion of
azotic gas mixed with the oxygen gas; and that
only about one fifth-part of the air employed is
abforbed, becaufe, as the oxygen gas only is ab-
forbed, the proportion of the azotic gas becomes
fo great towards the clofe of the experiment, as
to put an end to the combuftion.

I

XL£M£NTS

-^ tw akcsdj ihcwiv that pholpfaorus is
^am^i ky tawhafcoa into an cxcremelx light,
Its properties are Ukewife
by tkii tramfcMmation ; from
hcaig iafahiblc in water, it becomes not onl/
to!abfe, bm (o greedy of moiSnre, as to anrad
tbe hiffluditr of the air with RftonifliiDg rapidi-
ty ' By thU means it is conrerced into a liquid,
confiderabl; more denfe, and of more fpedflc
giavity than water. la tbe flate of phofphorus
before combuftiou, it had fcarcely any fenfible
taAe ; by its unioo with oxygea it acquires an
eitrcmely fharp aod four tafte ; in a word, from
one of the dafs of ctnmbuHible bodies, it is cbao-
j^ into an tncombuflible lubftance, and becomes
oacof ihofe bodies called acids.

This pn^rty of a combufUble fubftancc to
be coQTerted into an acid, by the addition of
, we- ifaaU prcfently find belongs to a great
rofbodi»: Wherefore, ftrift logic re-
ojlirak tbst we fcoaid adopt a common term for
' aU tJMic operations which produce
I nTdhs. This is the true way to lini-
fl^ ^ Ito^v «c feieiKe, as it would be quite
ear all its fpectfical details in
they were not clallicalty ar-
t<Mgg«>l^ Ker rius reafoo, we llutU dilbnguifli
»•» rt^«rc<*tM» o*" pbo^ifaonis iulo tn acid, by
tM MtU4A witti «x.v^ciw utA ia general every
t\W)vuwttv^» nt «cj5ea with-tt combDAible fub-
Aance,

»

OF CHEMISTRY. m

Ofloce, by the; term td tiygenation : rrom ithis

I fhttU adopt, the verb Xoi oxygenate ; and of cod-
fequcnce OibU fay, that in axygenattag phofpho'
rus we conrert it into an acid.

Sulphur is Itkenife a combuftible bodj, pr, in
other words, it is a body which pofleflcs the
power of decompofing oxygen gas, by attrafl-.
ihg the oxygen fVam the caloric with which it
was coittbincd. This can very eallly be proved,
by meaos of experlaiems tjuite finiilar to thofc
we liaw given nriri) phofphorus ; but it h ne-
cetTary to premife, that in tiiefe operations with
fulphur, th« feme accuracy of rcfult is not to
be expected as with phorphonis ; becaufe the
acid vrhich is formed by the combuQioii of ful-
phur is difficultly condenQble, and becaufc fal-
phur bums with more difficulty, and is foluble
in the different gaffes. But 1 can fafely aflert,
fi-om my own experiments, that fulphur in
burning abforbs oxygen gas ; that the refuhing
acid is coa£dcrably besvier than the fulphur
buritt ; that its weight is equal to the fura of
tlie weights of the fulphur which has been
burnt, and of the oxygen abforbcd ; and, iaftly,
that this acid is weighty, incombuftible, and
mifcible with water in all proportions. The only
uncertainty remaining upon this head, is with
regard to the propoitions of fulphur and of
oxygen which enter into ihe comjioStJon of the
acid. , ,,

Charcoal,

Ctmtqii^ which, from all our prcTent knowfil
•^^ •vCNttug^ it, muft be confidtred as a fim-
J»t!««fc(dhble body*, has likcwife the proper-
^ a* decompofing oxygen gas, by abforbing its
%M 6tHn the caloric : But the acid refuhing
Iiiim this combuftion does not condenfe in the
common temperature ; under the preffure of our
itmofphere, it remains in the ftate of gas, and
requires a large proportion of water to combine
with, or be diiTolved in. This acid has, how-
CTer, all the known properties of other acids,
though in a weaker degree, and combines, like
them, with all the bafes which are fufceptible of
forming neutral falts.

The combuftion of charcoal in oxygen gas,
may be effected like that of phofphorus in the
bell-glafs, A, PI. IV. 6g. 3. placed over mer-
cury: But, as the heat of red-hot iron is not
fulBcient to fet fire to the charcoal, we muft
add a fmall morfel of tinder, with a minute
particle of phofphorus, in the fame manner as is
dirc^ed in the experiment for the combuftion
of iron. A detailed account of this experiment
will be found in the memoirs of the academy

for

* This aflcTtlan is to be underflood of the pure combufU-
ble part of charcoal, whicb, in the nomenclature, is named
carbon, carionum, to dillingiill}i it from charcoAl, chaTbon,
cariro -. The latter, beGdes carbon, contains Tome incoir-
bi^ible cin!j, and certain falts. T.

OF CHEMISTRY. 113

for 1781^ p. 448. By that experiment it ap-^
pears, that 28 parts bj weight of carbon re«
quire 72 parts of oxjgen for faturation, and that
the aeriform acid produced is precifely equal
iii weight to the fum of the weights of the char-
coal confumed and oxygen gas employed during
the combuftion. This aeriform acid was called
fixed or fixable air by the chemifts who firft dif-
covered it; they did not then know whether it
was air refembling that of the atmolphere, or
fome other elaftic fluid, vitiated and corrupted
by combuftion ; but fince it is now afcertained to
be an acid, formed like all others by the oxy-
genation of its peculiar bafe, it is obvious that
the name of fixed air is quite ineligible *.

By burning charcoal in the apparatus men-
tioned, p. 60, Mr de la Place and I found that
one lib. of charcoal melted 96.375 libs, of ice ;
that, during the combuftion, 2.57 14 libs, of oxy-
gen were abforbed, and that 3.5714 libs, of acid
gas were formed. This gas weighs 0.695 parts
of a grain for each cubical inch, in the common

H ftandard

• It may be proper to remark, though here omitted
by the author, that, in conformity with the general prin-
ciples of the new nomenclature, this acid is by Mr La-
voifier and his colleagues called the carbonic acid, and
when in the aeriform ftatei carbonic acid gas. — T.

114

ELEMENTS

ftandaril temperature and prelTure mentioned
above, fo that 34242* cubical inches of acid gas
are produced by the combuftion of one pound of
charcoal.

I might multiply thefe experiments, and ftiow»
by a numerous fucccHion of fa<fts, that all acids
are formed by the combuflion of certain fubftan-
ces ; but 1 ain prevented from doing fo in this
place, by the plan which I have laid down, of
proceeding only from fads already aicertained
to fuch as are unknown, and of drawing my
examples only from circumftances already ex-
plained. In the mean time, however, the
three examples above cited may fulHce for gi-
ving a clear and accurate conception of the
manner in which acids are formed. By thefe
it may be clearly feen, that oxygen is an ele-
ment common to thepi all, and which confti-
I tDtes or produces their acidity^ and that they
F' differ from each other, according to the feveral
natures of the oxygenated or acidified fubHan-
ces. We muft therefore, in every acid, care-
fully

* Some eiTor muil havt crept into Mr Lavoifier's cal.

adon ; for, on die data litre given, the number of cu>
Jiical incites of gas ought to have been 47358.3; as 3.5714
/((f. of catbonic acid gas, or 31914.0114^^. when di-
vided by -69J, the weight of a cubical inch, give thi."
corrc^lfd quotient.— T.

OF CHEMISTRY.

"5

fully diftinguifh between the actdifiable bafe,
which Mr de Morveau calls the radical, and
the acidifying priaciple» or oxygen.

H2

CHAP.

E L E ME NT S

CHAP. VI.

Of the Nomenclaiure of Acids in general, and par*
ticttlarly of tbofe drawn from Nitre and Sea-
Salt.

IT becomes extremely eafy, from the princi-
ples laid down in the pieceding chapter, to
eftablilh a fyftematic nomenclature for the a-
cids : The word acid being ufed as a generic
term, each acid falls to be diftinguilhed in lan-
guage, as in nature, by the name of its bafe or
■idiL.il. Tlmg. we give llie LTcneric name of

r

I

OF CHEMISTRY.

117

niih us with examples. When fulphur is com-
bined with a fmall proportion of oxygen, it
forms, in this firft or fower degree of oxygena-
tion, a volatile acid, having a penetrating odour,
and poflefled of very peculiar qualities. By a
larger proportion of oxygen, it is changed into
a lixed, heavy acid, without any odour, and
which, by combination with other bodies, gives
produdts quite different from thofe furnilhed
by the former. Id this inftance, the principles
of our nomenclature feem to fail; and it appears
difficult to derive fuch terms from the name of
the acidifiable bafe, as fliall diftinftly cxprefs
thefetwo degrees of faturation, or oxygenaiion,
without circumlocution. By refledion, how-
ever, upon the fubjefl, or perhaps rather from
the neceffity of the cafe, we have thought it al-
lowable to exprefs thefe varieties in the oxyge-
nation of the acids, by Cmply varying the termi-
nation of their fpecific names. The volatile acid
produced from fulphur \vas anciently known
to Stahl under the name of ftilpburous acid *.
H 3 We

• The term formerly ufed by the EngliOi chemifts for
(hb ftcid wi£ wntCen fulphureous ; but I liave thought pro-
per to fpell it as above, that it may better coDform with the
jimilar terminations of nitrous, carbonous, &c. to be ufed
Iicreaflcr. In general, I hare ufed the Englilh terminations
ic and oiu to tranCate the terms of the Author which end
with iqut and rux, with hardly any other alterations. — T.

xa

ELEMENTS

We hive preferred tliat term for this acid from
fulphur ander-&taTsted with oxgjrgen ; and di-
fiiiiguiih the other, or completely faturated or
oxygenated acid, by the name of /ulpburic acid.
AVe ihall therefore fay, in this new chemical
hiijuage, that fulphur, in combining with ox^
gt.:n, is .'fufceptible of two degrees of faturation;
that the firft, or lefler degree, conftitutes ful-
phurous acid, which is volatile and penetrating^
while the iecond, or higher degree of iaturation,
produce fulphuric acid, Which is fixed uid in-
odorous. We (ball adopt thi> difference of ter-
mination for all the acids which aflume fevera]
degrees of faturation. Hence -we have a phof-
phorous and a phofphoric acid, an acetous and

OF CHEMISTRY.

Imown, names were kdopted for the two, which
have not the fmalleft connexion ; and thus,
not only the memory became burdened with
nfelefs appellations, but the minds of ftudents,
nay even of experienced chemifts, became fil-
led with falfe ideas, which time and reflectioa
alone are capable of eradicating. We may
give an inftance of this confiifion with refpeft
to the acid of fulphur : The former chemifts,
having procured this acid from the vitriol of
iron, gave it the name of the vitriolic acid from
the name of the fubftancc which produced it ;
and they were then ignorant that the acid pro-
cured from fulphur by coinbuftion was exaftly
the fame. The fame thing happened with the
aeriform acid, formerly called Jixed air ; il not
being known that this acid was the refult of
combining carbon with oxygen, a variety of
denominations have been given to it, not one
of which conveys jull ideas of its nature or ori-
gin.

We have found it extremely ealy to correft
and modify the ancient language with refpeft
to thofe acids which proceed from known bafes;
having converted the name of vitriolic acid into
that of/ulpburic, and the name of fixed air in-
to that of carbonic acid: But it is impoflible
to follow this plan with the acids whofc bafes
art; flill unknown ; with thefe we have been
obliged to ufe a contrary plan, and, inftead of
H 4 fotniing

E LE MI N-T S

forming the name of the acid from that of its
bafe, have been forced :to denominate its. uni-
known bafe from the n&nie of the known acid,
as happens in the cafi) qf the acid which is pro-
cured from fea-falt.

To difengage this acid from the alkaline bafe
with which it is combined, we have only to
pour fulphuric acid upon fea^falt ; immediately
abciflc eflfervefcence cakes place, white vapours
arife, of a very penetrating odour, and, by gen-
;tly hfating the mixture, all the acid is driven
off. As, in the common temperature and pref-
fure of our atmt^phere, this acid is naturally in
the ilate of gas, we tftM^ ufe particular precau^
tions for retaining it ii^ proper veOels. For fmall
experiments, the moft fimple and moft com-

OF CHEMISTRY. 121

places. When the difengagement of the gas
flackens, a gentle heat is applied to the retort,
and is gradually increafed, till nothing more
paffes over. This acid gas has a very flrong
affinity with water, which abforbs an enormous
quantity of it ; this is proved by introducing a
very thin layer of water into the glafs which con-
tains the gas, for, in an inflant, the whole acid
gas difappears, and combines with the water.
: .This latter circumftancc is taken advantage of
in laboratories and maiiufai^ories, on purpofb to
obtain the acid of fea-falt in a liquid form ; and
for this purpofe the apparatus PI. IV. Fig. i. is
employed. It confills ; of a tubulated retort A,
into which the fea-falt, and after it the fulphuric
acid, are introduced through the opening H;
of the balloon or recipient c, b, intended for
containing the -Iraall quantity of liquid which
pafles over during the procefs ; and of a fet of
bottles with two mouths, L, L, L, L, half filled
with water, intended for abforbing the gas dif-
engaged by the diftillation. This apparatus will
be more amply defcrjbed in the latter part of this
work.

Although we have not yet been able, either
to compofe or to decompound this acid of fea-
falt, we cannot have the fmallefl: doubt that it,
like all other acids, is compofed by the union
of oxygen with an acidifiable bate. We have
therefore called this unknown fubftance the
muriatic

^

ELEMENTS

muriatic hafe, or muriatic radical, deriving tliis
rame, after the example of Mr Bergman and
Mr de Morveau, from the Latin word muria,
which was anciently ufcd to fignify fea-fait.
Thus, without being able exadly to determine
the component parts of muriatic acid, we defign
by ;hat term a volatile acid, which retains the
form of gas in the common temperature and
preflure of our atmofphere ; which combines
with great facility, and in great quantity, with
water ; and whofe acidiSable bafe adheres fo
very intimately with oxygen, tint no method
has hitherto* been devifed for feparating them.
If ever this acidifiable bafe of the muriatic acid
is difcovered to be a known fubftance, though
now unknown in that capacity, it will be requi-
fite to change its prefent denomination for one
analogous with that of its bafe.

Id

• Dr Girtanner is faid to have lately difcovered that
Hydrogen h the bafe or radical of this acid. Should (his
difcovery be confirmed, the terms will here require fome
farther alteration, in conformity with the general prin-
ciples of the new nomenclature. At any rate, muriogea
may be employed to denominate the bafe of the muria-
tic acid, till its nature be unequivocally determined ; and,
if the difcovery attributed to Dr Girtanner be afcertalned,
the common bafe of water and muriatic acid will more
properly fall to be named by this new tci m^ than by that
of Hydrogen. T.

[

OF CHEMISTRY.

"3

In common with fulphuric acid, and feveral
other acids, the muriatic is capable of different
degrees of oxygenation ; but the escefs of oxy-
gen produces quite contrary effects upon it from
what the fame circumftance produces upon the
acid of fulphur. The lower degree of oxygena-
tion converts fulphur into a volatile gafieous
acid, which only mixes in fmall proportions
with water ; while a higher oxygenation forms
an acid pofleifing much ftronger acid proper-
ties, which is very fixed, and cannot remain in
the flate of gas, but in a very high temperature,
which has no fmell, and which mixes in large
proportion with water. With muriatic acid,
the direct reverfc takes place ; an additional
faturation with oxygen renders it more volatile,
of a more penetrating odour, lefs mifcible with
water, and dirainilhes its acid properties. Wc
were at firft inclined to have denominated thefe
two degrees of faturation in the fame manner
as we had done with the acid of fulphur, call-
ing the lefs oxygenated munatous acid, and
that which is more faturated with oxygen m,<-
riatic acid : But, as this latter gives very par-
ticular rcfults in its combinations, and as no-
thing analogous to it is yet known in chcmif-
try, we have left the name of muriatic acid
to the Icfs faturarcd, and give the latter the
more

IM

ELEMENTS

more compounded ^pellation of oxygenated nu-
riatic acid *.

Although the bale or radical of the acid
which is estradod from nitre or faltpetre be
better known, we have judged proper only
to modify its name . in .the fame manner with
that of the muriatic acid. It is procured from
nitre, by the interrsntton of fulphuric acid,
by a proce& fimilar to that defcribed for ex-
trading the muriatic acid, and by means rof
the fame apparatus, PL 'IV. Fig. i. In propor-
tion as the acid paflTes over, it is in part con-
denfed in the balloon or recipient^ and the reft
is abforbed by the water contained in the bot<
ties L« L, L, L ; the water becomei firft green,
then blue, and at laft yellow, in proportion to

H OF

CHEMISTRY.

■was well afcettained. Its two conftituent ele-
ments are but weakly united, and are eafily
feparated, by prefenting any fubftance with
which oxygen has a ftronger affinity than with
the acidiSable bafe peculiar to this acid. By
fome experiments of this kind, it was firft dif-
covered that azot, or the bafe of mephitis or of
azotic gas, conftituted its acidifiable bafe or
radical ; and cocfequently, that the acid of
nitre was really an azotic acid, having azot for
its bafe, combined with oxygen. For thefe
reafons, that we might be confiftent with our
principles, it appeared neceflary, either to call
the acid ai^otic, or to name the bafe nilrie ra~
dical i but from either of thefe we were dif-
fuaded, by the following confiderations. It
feemcd difficult to change the name of nitre
or faltpetre, which haxe been univcrfally ad-
opted in fociety, in manufafturcs, and in che-
miftry, and, on the other hand, axot having
lieen difcovered by IMr Berthollet to be the
bafe of volatile alkali, or ammoniac, as well as
of this acid, we thought it improper to call it
nitric radical. We have therefore continued
tlie term of aiot to the bafe of that part of
atmofpheric air which is likewife the nitric
and ammoniacal radical ; and we have named
the acid of nitre, in its lower and higher de-
grees of oxygenation, nitrout acid in the for-

126

ELEMENTS

mer, and nitru: acid in the latter fiate; thus
preferving its former appellation pn^rly modi-
fied.

Several vcrj refpedable chemilb have dif-
upproved of this deference for the old terms,
and wifhed us to have perfevered in perfe£Ung
a new chemical language, without paying any
refped to ancient ufage ; fo that, by thus (leer-
ing a fort of middle courfe, we have expofed
ourfelves to the cenfures of one fed of che-
mifts, and to the expollulations of the oppolite
party.

, The acid of nitre is fufceptible of afluming a
great number of feparate ftates, depending up-
on its degree of oxygenation, or upon the pro-

r

OF CHEMISTRY.

127

one of the methods for determining the quantity
of oxygen gas mixed with any portion of air,
and confequently is ufed as a te(t for afcertain-
ing its degree of falubrity.

The further addition of oxygen converts
the nitrous gas into a powerful acid^ which
has a ftrong affinity with water, and which
is itfelf fufceptihle of various additional degrees
of oxygenation. When the proportions of
oxygen and azot are below three parts, by
weight, of the former to one of the latter, the
acid is red coloured, and emits copious fumes.
Id this ftate, by the application of a gentle
heat, it gives out nitrous gas ; and we terra
it, in this degree of oxgenation, nitrous acid.
When four parts, by weiglit, of oxygen, are
combined with one part of aiot, the acid is
ciear and colourlcfs ; more fixed in the fire
than tbe nitrous acid ; has kfs odour, and
its conlltCuent elements are more firmly uni-
ted: This fpecies of acid, in conformity with
our principles of nomenclature, is called nitric
acid.

Thus, nitric acid is the acid of nitre, fur-
charged with oxygen ; nitrous acid is the acid
of nitre furcbarged with aiot, or, what is the
Gime thing, with nitrous gas ; and this latter is
azot not fufficiently faturated with oxgen to
polTefs the properties of an acid. To this lat-

128 ELEMENTS

ter degree of oxygenation, we have afterwards,
in the courfe of this work, given the generical
name of oxyd *.

i

• In Urift cotifortnity with the principles of ttie new
nomenclature, but which the author has given his reafons
for deviating from in this inRance, the following ought to
have been the terms for azot, in its feveral degrees of oxy-
genation ; Au3t, azotic gas, (azot combined with caloric},
azotic oxjd gas, aiotous acid, and azouc add. — T.

OF CHEMISTRY* 129

CttAP. tiL

t)f the Decompojition tf Oxygen Gas bjf means of
Metals^ and the Formation of Metallic Oxyds.

OXYGEN has a ftronger affinity with me-
tals that are belated to a certain degree
than with caloric : In confequehce of this, all
metallic bodies, excepting gold, filver, and pla-
tina, have the property of decompofing oxy-
gen gas, by attrading its bafe from the caloric
with which it was combined. We have already
ftiown in what manner this decompofition is ef-
fected by means of mercury and iron ; having
obferved, that, in the cafe of the firft, it mull
be confidered as a kind of gradual combuftion^
whereas, in the latter, the combuilion is ex-
tremely rapid, and is attended with a brilliant
flame. The ufe of the heat employed in thefe
operations is to feparate the particles of the me-
tal from each other, and to diminifh their at-
tradion of cohefion or aggregation, or, what is
the fame thing, their mutual attradion for each
other.

The abfolute weight of all metallic fubftan-
ces is augmented in proportion to the quantity

1 of

138

£:l£; M£ NTS

ter degree of oxjgenatioa, we hare afterwards,
in the courfe of this work, given the generical
name of oxjd*.

CHAP.

« In flrid coliformitj w!di tbe principles cf tlie new
nonen cloture, but irtiich the author has given hit reafbns

OF CHEMISTRY.

H'

I

ged by fire into an earthy alkali, by lo/in^ half
of iK weight; and metals, which, by die fame
means, have joined tliemfelves to a new fub-
ftance, the added quantity o£ which often ex-
Veeds half their weight, and by the addition of
which they have been changed alnioft into the
nature of acids. This mode of claflifying fub-
itaoces, of fo very cjppolite natui'es; undec the
fame generic name, would have beca quite coii^
irary to our principles of nomenclature ; cfpe-
cially as, by retaining the above terra for this
ftate of metallici fubftances, wemuft have con-
veyed very falfe ideas of its nature. We have^
therefore, laid aiide the cupteiTwa metallic calx
altogether, and have fubftituted in its place the
term Qxyd, from the Greek word c^wj.

By this readinefs for fupplying appoGte terms,
it is evident that the language we have adopt-
ed is both copious and e^prcffive. The drft
or loweft degree of oxygenation in bodies, con-
vert* them into oxydf ; a fecond degree of ad-
ditional oxygenation conftilutes that clafs of
acids, of which the fpecific names, drawn fioni
their particular bafes, terminate in ous, as the
nitroui and falphhrous acidS ; the third degret-
of, oxygenation changes thcf? into that dlvifiou
of acids, which are diftinguifticd by the termi-
nation: ip , if, as \\\^ nUric ^t\&. fulphutic acids v
and, laftly, we can exprcfs a fourth, or highc(l)
degree nf orl-gEnalion, by adding the word oxy-
I n. genotfii

»3o

ELEMENTS

of oxygen they abforb ; they, at the fame timci,
lofe their metallic fplendour, and are reduced
to the appearance of an earthy pulverulent mat-
ter : In this ftate, metals mull not be confider-
ed as entirely faturated with oxygen, becaufe
their adion upon this element is countcr-b&>
lanced by the power of affinity between it and
the caloric. During the calcination of metals,
the oxygen is therefore aiiled upon by two fe-
purate and oppofite powers^ that of its attrac-
tion for caloric, and that exerted by the metal ;
and it only tends to unite with the metal in
confequence of the excefs of the latter power
over the former, which is, in general, very
inconfiderable. Wherefore, when metallic fub-

m

OF CHEMISTRY. 135

CHAP. VIIL

Of the Radical Principle of fVater, and x>f its
Decompofition by Charcoal and Iron.

UNTIL very latdy, water has always been
thought a fimple fubftance ; infomuch
that the older chemifts con0dere4 it as an ele«
ment. Such it undoubtedly was to them, as
they were unable to decompofe it ; or, at leaft,
fince the decompofition which took place daily
before their eyes, was entirely unnoticed. But
we mean to prove, that water is by no means a
fimple or elementary fubflance. I fhall not
here pretend to give the hiftory of this recent,
and hitherto contefted difcovery, which is de-
tailed in the Memoirs of the Academy for 1781,
but fhall only bring forward the principal
proofs of the decompofition, and compofition of
water ; and I may venture to fay, thatthefe will
be convincing to fuch as confider them impar-
tially.

Experiment Firjl.

Having fixed the glafs tube EF, Plate VII.
fig. ir, of from 8 to J2 lines diameter, acrofs a

1 4 furnace,

'34

■ELEMENTS

and accurate ideas of the correfponding objeSa
which we wifli to exprefs by their ufe. All this
will be rendered perfectly clear and diflinft by
means of the tables which are added to this
work.

d

OF CHEMISTRY. 135

CHAP- VIII.

Of the Radical PHndple of Water, and of Us
Decompofition by Charcoal and Iron.

UNTIL very lately, water has always been
thought a iimple fubftance ; infomuch
that the older chemifts con(idere4 it as an ele«
meat. Such it undoubtedly was to them, as
they were unable to decompofe it ; or, at leaft,
fince the decompofition which took place daily
before their eyes, was entirely unnoticed. But
we mean to prove, that water is by no means a
fimple or elementary fubflance. I fhall not
here pretend to give the hiftory of this recent,
and hitherto contefted difcovery, which is de-
tailed in the Memoirs of the Academy for 1781,
but fhall only bring forward the principal
proofs of the decompofition, and compofition of
water ; and I may venture to fay, that thefe will
be convincing to fuch as confider them impar-
tially.

Experiment Firjl.

Having fixed the glafs tube EF, Plate VII.
fig. ir. of from 8 to 12 lines diameter, acrofs a

1 4 furnace,

'3*5

ELEMENT!

furnace, with a fmall inclinatiorf from £ ta F ;
lute the fuperior extremity £ to the gla(a retort
A, containing a determinate quantity of diftil-
led water ; and to the fuperior extremity F, lute
the worm SS, fixed into the neck of the doubly
tubulated bottle H ; which latt l^as the bent tube
KK. adapted to one of its openings, in fuch a
manner as to convey fuch aSriform flntds o^
galTes as may be difengaged, during the experi-
ment, into a proper apparatus for determining
their quantity and nature.

To render the fuccefs of this experiment cer- .
^0, it is neceflary that the tube £F be made
of well ann^led and difficultly fullble glafs, and
that it be coated over with a lute compofed of
clay mixed with powdered ilone-ware; belides

OF CHEMISTRY. 135

/

CHAP. VIII.

Of the Radical PHndple of Water, and of its
Decompofition by Charcoal and Iron.

UNTIL very lately, water has always been
thought a fimple fubftance ; infomuch
that the older chemifts confidere4 it as an ele«
ment. Such it undoubtedly was to them, as
they were unable to decompofe it ; or, at leaft,
fince the decompofition which took place daily
before their eyes, was entirely unnoticed. But
we mean to prove, that water is by no means a
fimple or elementary fubflance. I fhall not
here pretend to give the hiftory of this recent,
and hitherto contefted difcovery, which is de-
tailed in the Memoirs of the Academy for 1781,
but fhall only bring forward the principal
proofs of the decompofition, and compofition of
water ; and I may venture to fay, that thefe will
be convincing to fuch as confider them impar-
tially.

Experiment Firjl.

Having fixed the glafs tube EF, Plate VII.
fig. ir. of from 8 to 12 lines diameter, acrofs a

1 4 furnace,

138 ELEMENTS

i-F : Every thing elfe is managed exactly as ia
the preceding experiment.

The water, contained in the retort A, is dillll-
led, as in the former experiment, and, being
condenfed in the worm SS, falls into the bottle
H ; but, at the fame time, a confiderable quan-
tity of gas is difengaged, which, efcaping by the
tube KK, is received in a convenient apparatus
for that purpofe. After the operation is finiflir
ed, we find nothing but a few atoms of a/hes re-
maining in the tube EF ; the ab grs. of charcoal
having entirely difappeared.

When the difengaged gaffes are carefully exa-
mined, they are found to weigh 113.7. ^r/.*;
thefe are of two kinds, viz. 144 cubical inches
of carbonic acid gas, weighing \oo grs. and 380
cubical inches of a very light gas, weighing
only l^'T grs.\ this latter gas takes fire, when
in contaifl with air, by the approach of a light-
ed body ; and when the water which has paf-
Itd over into the bottle H is carefully examined,
it is found to have loft 85.7 jr/. of its weight.
Hence, in this experiment, 85.7 ^''J- of water,
joined to 28 grs. of charcoal, have combined
in fuch a way as to form 100 grs. of carbonic
acid,

* la the latter part of this work, will be fouud a parti'
cular account of the proccCTcs ncccHary for fepaniiing tbp

different kinds of galTcs, cjid for determining tbcir quaa«fl
titles, and the particular natures of each,— T.

OF CHEMISTRY.

'3!l

I

acid, and iS-y^f/. of a particular gas capable
of being burnt.

I have already ftiewn, that loo gri. of carbo-
nic acid gas confift of 72 jT/. of oxygen, com-
bined with 28 gri. of carbon ; hence the 18 jrj.
of charcoal placed in the glafs tube have acqui-
red 72 ^f/. of oxygen from the water; and it
follows, that 85.7 grs. of water are compofed
of ']i grs. of oxygen, combined with i'^-j grj.
of a gas fufceptible of combuftion. We fliall
fee prefently that this gas cannot poflibly have
been difengaged from the charcoal, and mufl:
confequently have been produced from the wa-
ter.

I have fupprefled fome circumftances in the
above account of this experiment, which would
only have rendered it complicated, and made
its refult! obfcure to the reader. For inflance,
the inflammable gas difiblves a very fmall part
of the carbon, by which means its own weight
is fomewhat augmented, and that of the car-
bonic gas is proportionally diminifhed. Al-
though the alteration produced by this cir-
cumftance is very iiiconfiderable, yet I have
thought it neceflary to determine its effefts by
a rigid calculation, and to report, as above, the
refultB of the experiment in its fimpiified ftatc,
as if this circumftancc had not happened. At
any rate, fliould any doubts remain refpeiSing
llic conitqiicnces I have drawn from this experi-

140 £L£M£NTS

loeqt, they vrill be fully diffipated by tbeibllow.
iDg experiments, which I am gpipg toaddncp
in fuppQrt of jay opinion.

Experimit Third.

Tl^e apparatus being dirppfed exadly as.jq
the former experiiaent, with this difference,
that indead of the %% grs. of charcoal, the tuba
HF is filled with z'j^grs. of foft iron, in thin
plates, rolled up fpfrally. '^he tube is made
red hot by me^ns of its furnace, and the water,
in the retort A, is kept conftantly boiling till
it be all evaporated, and has paffed through the
tube £ F, to be condenfed in the bottle H.

No carbonic acid is difengaged in this

^ its mai

OF CHEMISTRY.

I

Mi

its magnitude is confiderablj augmented. The
iron is now hardly attrafiable by the magnet ; it
diffolves in acids without effervefcence ; in (hort,
it is converted into a black oxyd, precifely fimi-
lar to that produced by the combuftion of iron
in oxygen gas.

In this experiment we have a true oxydalhn
of iron by means of water, exaijtly fmiilar to
that produced in air by the affiftance of heat.
One hundred grains of water having been de-
compofed, 85 gri. of oxygen have combined
with the iron, fo as to convert it into the ftate
of blaclt oityd, and 15 /r/. pi' a peculiar inflam-
mable gas are difengaged : From all this it
clearly follows, that water is compofed of oxy-
gen combined with the bafe of an infiammable
gas, in the rcfpeftjve proportions of 85 parts,
by weight of the former, to 15 parts of the lai-

f Thus water, befides the oxygen, which is
one of its elements, as it is of many other fub-
ftaoces, contains another clement as its con-
ftituent bale or radical, and for this proper
principle or clement we mud find an ap-
propriate term. None that we could think
of feemed better adapted than the word hy-
drogen, which {ignifics the generative prin-
ciple of 'jiatfr. from Cfua nqtia, and yimejAXi gig-

141

ELEME N-T S

nor*. We callithecombinatiouiof this.e)£ment
with caloric bydrcgtH gat-i and itbc [term hydro--
gen-f: expre£rcsthcllafex>f that gaSf'Ctf the NUi-
calofwatcr. ■• ■■.-■. . ^:. . ^ ■. .. ~-

This experiment fiirnifiies nsowjth a nev
combuflible body, or, in other wordii a/body
which has fo much afiiaity with 'xixTgenias to
draw it from its conneftioh with c^ric, and to
dccompofe oxygen ^. .This consbuflibl^bo^
has itfelf fo great an affinity with caloric, that,'
unlefs when engaged ia a combinatttm jKith foioe
other body, it always fubfifts in the i aeriform
or galTeous ftate, in.' the ufual temperature and
prclTure of our atmofphere. In thti ftate of gas
it is about -yJ- of the weight of an equal bulk of

OF CHEMISTRY. 143

fitmofpheric air j it is not abforbed by water^
though it id capable of holding a fmall quantity
of that fluid in folution ; and it is incapable of
being ufed for refpiration, without producing in-
itant death.

As the property of b,urning, which this gas
poflefles in common with all other combuftible
bodies, is merely the power of decompofing
air, and carrying off its oxygen from the calo-
ric with which it is combined, it is eaflly 'Under-
ftood that it cannot bum, unlefs in contadl with
air or oxygen gas. Hence, when we fet fire to
a bottle full of this gas, it burns gently, firft at
the neck of the bottle, and then in the infide of
it, in proportion as the external air gets in :
This combuftion is flow and fucceflSve, and on-
ly takes place at the furface of contadl between
the two gaffes. It is quite different when the
two gaffes are mixed before they are fet on fire ;
If, for infl:ance, after having introduced one
part of oxygen gas into a narrow-mouthed
bottle, we fill it up with two parts of hydrogen
gas, and bring a lighted taper, or other burn-
ing body, to the mouth of the bottle, the corn-
bullion of the two gaflcs takes place inftanta-
neoui^y with a violent explofion. This experi-
ment ought only to be made in a bottle of very
llrong green glafs, holding not more than a
pint, and ftrongly wrapped round with twine,
other wife the operator will be e\pofed to great

danger

i44

ELEMENTS

danger from the raptare of the bottle, of whicti
the fragments will be thrown about with great
force.

If all that has been related above, concern-
ing the decompofition of water, be exailly con-
formable to truth \ — if, as I have endeavoured
to prove, that ftibftance be really compoied of
hydrogenj as its proper conftituent elemetit,
combined with oxygen, it ought to follow, that
by reuniting thefe two elements together^ we
fliould recompofe water ; and that this a<flual-
ly happens, may be Judged off by the following
experiment.

OF CHEMISTRY. 145

gas contained in the tefervoir is forced, with a
moderate degree of quicknefs, by the prefiure
of one or two inches of water. The fourth
tube contains a metallic wire GL, having a knob
at its extremity L, intended for giving an elec-
trical fpark from L to d'^ on purpofe to fet fire
to the hydrogen gas : This wire is moveable in
the tube^ that we may be able to feparate the
knob L from the extremity d' of the tube D d\
The three tubes d D d' gg^ and Hh, are all pro-
vided with ilop-cocks.

That the hydrogen gas and oxygen gas may
be as much as polSble deprived of water, they
are made to pafs, in their way to the balloon A,
through the tubes MM, NN, of about an inch
diameter, and thefe are filled with falts, which,
from their deliquefcent nature, greedily attradl
the moifture of the air : Such are the acetite

«

of potafh, and the muriat or nitrat of lime *.
Thefe falts mull only be reduced to a coarfe
powder, left they run into lumps, and prevent
the gaffes from getting through their inter-
ftices.

We muft be provided before hand with a
fufficient quantity of oxygen gas, carefully pu-

K rified

* See the nature of thefe talts ifl the fccond part of this
book.— A.

146

ELEMENTS

liSed from all admixture of carbonic acid^ hy
long contact with a folution of potalh' *.

We mud like^ife have a quantity of hydro-
gen gas, equal to twice the bulk of the oxygen
gas, and contained in a feparate referroir : this
muft he carefully purified in the fame manner by
long contact with a folution of potafli in water.
The bcft way to obtain this gas free from mix-
ture is, by decompofing water with pure foft
iron, as directed in Exp. 3. of this chapter.

Having adjufted everything properly, as a-
bove direfted, the tube H h is adapted to an air-
pump, and the ballon A is exhaafted of its air.
We next admit the oxygen gas, fo as to fill the
balloon ; and then, by means of preflbre, as h

OF CHEMISTRY. 147

fumed* I have in another place * given a mi-
nute defcription of the apparatus ufed in this ex-^
perimenty and have explained the manner of af-
certaining the quantities of the gaffes confumed
with the moft fcrupulous exaftitudc.

In proportion to the advancement of the
combuftion, there is a depofition of water upon
the inner furface of the balloon or matrafs A :
The water gradually increafes in quantity, and;
gathering into large drops^ runs down to the
bottom of the veffel. It is eafy to afcertain
the quantity of water colledted, by weighing
the balloon both before and after the experi-
ment. Thus we have a twofold verification
of our experiment, by afcertaining both the
quantities of the gaffes employed, and of the
water formed by their combuftion : Thefe two
quantities muft be equal to each other. By
an operation of this kind, Mr Meufnier and I
afcertained that it required 85 parts by weight,
of oxygen, united to 15 parts of hydrogen, to
compofe one hundred parts of water. This ex-
periment, which has not hitherto been publifli-
cd, was made in prefence of a numerous com-
mittee from the Academy of Sciences. We ex-
erted, on that oocafion, the moft fcrupulous at-
tention to accuracy ; and have reafon to bc-

K 2 lieve

* See the third part of this work. — A.

ELEMENTS

CHAP. IX.

Of the ^lanthies of Caloric difen^aged during dif-
ferent Species qf Combuftian.

IT. has been already mentioned, that when
equal quantities of difiereot bodies arc burnt
in the centre of a hollow fphere of ice, and are
fupplied with air at the temperature of 32^,
the quantities of ice melted from the infide of
the fphere, become meafures of the relative
quantities of caloric difcngagcd during the fe-
veral combuftions. Mr de la Place and 1 have
iiivcii a Ueilrintion of ihe anparatus employed

m

OF CHEMISTRY.

i^i

One pound of charcoal melted^6.5 //ij.

One pound of hydrogen gas melted 295.5895
libs. ^ .. *

As a concrete ac^d. is formed by the combuf-
tion of phofphorus, it is probable that very little
caloric remains in the acid ; and, confequently,
that the above experiment gives us very nearly
the whole quantity of caloric contained in tl)e
oxygen gas. Even if we fuppofe the phofphoric
acid to contain a good deal of caloric, yet, as

the phofphorus muft have contained nearly an

* " - * .

equal quantity before combuftion, the error muft
be very fmall, as it will only confift of the dif-
ference between what was contained in the
phofphorus before, and in the phofphoric acid
after combuftion.

I have already ftiown, in Chap. V. that one
pound of phofphorus abforbs one pound eight
ounces of oxygen during combuftion ; and, fince
by the fame operation, 100 /ibs. of ice are melt-
ed, it follows, that the quantity of caloric con-
tained in one pound of oxygen gas ils capable of
melting 66.6667 //^j". of ice.

One pound of charcoal during combuftion
melts only 96.5 libs, of ice, whjlp it abforbs
2.5714 libs, of oxygen. By the experiment
with phofphorus, this quantity of oxygen gas
pught to difengage a quantity. of caloric fuffi-
cient to melt 171.414 libs, of ice ; confcquent-
ly, during this experiment a quantity of caloric

K 4 fufticient

152

ELEMENTS

fufRcient tp melt 74-914 Hi's, of ice di&ppcars.
Carbonic acid is hot, like phofphoric acid, in a
concrete ftate, after combuflion, but in the ftate
of gas, and requires to be united- with caloric to
enable it to fubfift in that ftate ; and the guan-
tit/ of caloric which is mifling in the lafl: expe-
riment is evidently employed for that purpofe.
When we divide that quantity by the weight
of carbonic acid, formed by the combutlion of
one pound of charcoal, we find that the quan-
tity of caloric, ncceflary for changing one pound
of carbonic acid from the concrete to the gafieous
ftate, would be capable of melting 22.9766 libs.
of ice.

Wc may make a fimilar calculation with the

I

OF CHEMISTRY. 153

•

Hence, as 6.6667 libs, of water are formed,
from the combuftioit of one pound of hydrogen
gas, with 5.6667 libs, of oxygen ; it follows
that, in each pound of water, at the tempera-
. ture of 32"*, there exifts as much caloric as
would melt 12.2708 libs, of ice ; without taking
jnto account the quantity originally contained
in the hydrogen gas, which we have ^been ob-
liged to omit, for want of data to calculate its
quantity*.* From this it appears that water,
even in the ilate of ice, contains a confider-

able

* From the general principles of the new chemical phi-
lofophy, hydrogen gas ought to contain a much larger
quantity of caloric for giving it the gafleous ftate than
oxygen gas. Being, thirteen tinges as rare, it may be fup-
pofed to contain thlrteeen times as much caloric. Hence,
if all the caloric of the two gailes were difengaged during
their combaftion, and the confequent formation of water,
1 244.4 1 67 liis, of ipe Aould have been melted; but only
295.1522 //3/. are melted, ^d therefore, on this fuppofi-
tion, the remaining caloric in 6.6667 /ids. of water would
be able to melt 94.92643 libs, of ice ; or each pound of
water at the temperature of 32^, fhould contain as much
caloric as is fnfiicieot to melt 142 libs, of ice nearly, which
is abfurd ; for one pound of water, at 32^, muft contain
pr^ifely aa much caloric as is neceflary to melt one pound
of ice. This ihews the fallacy of all reafonings drawn
from the fuppofable quandties of caloric in bodies ; ^nd
that we are hitherto very far from pofleffing any accurate
Ynovflccfge of that part of chemiftry in which caloric is
concerned .— r^T.

154 ELEMENTS

able quantity of caloric, and ^hat oxygen, in en-
tering into the combination, re,i;akis likewiTe a
good proportion.

From thefe experiments, we may aiTume the
following refults as fufficiently ellablifljed.

Combujlion of Pbojphorus.
From the combuftion of phofphorus, as related
in the foregoing experiments, it appears, that one
pound of phofphorus requires 1.5 /iJ. of oxygen
gas for its combuftion; and that 2.5 Khs. of
concrete phofphoric acid are produced.
The quantity of caloric difengaged by
the combuftion of one pound of
. phofphorus, exprefied by the num-
ber cf pounds of ice melted du- '.

9

OF CHEMISTRY. 155

Combnjlion of Charcoal.

■

In the combultion of one. pound of charcoal,
2.5714 libs, of oxygen gas are abforbed^ aqd
3.5714/^6/. of carbonic acid gas are formed:
Hence the ,

Caloric difengaged during the com-

bullion of one pound of charcoal *", 96.500CO
Caloric difengaged during the com-
buftion of charcoal, from each
pound of oxygen gas abforbed, 37.5a&23

Caloric difengaged during the forma-
tion of one pound of carbonic acid
gas, . - . - - 27.02024
Caloric retained by each pound of

oxygen after corabuftion, - 29.13844

Caloric neceffary for fupporting one
pound of carbonic acid in the ftate
of gas, ... - 20.97960

Comhujlion of Hydrogen Gas.

In the combuftion of one pound of hydrogen
gas, 5.6667 libs, of oxygen gas are abforbed,

and

obferved, the quantity it really contains is probably very
fmall, and we have not given it a value, for want of fuf*
ficient data to go upon. — A.

« All thefe relative quantities of caloric are exprefle4
by the number of pounds of ice, and decimal parts, meltr
c4 d^^iog ^^ feveraj operations.— T.

156

ELEMENTS

and 6.6667 ^^^^' °^ water are formed ; HencQ

the

Caloric difengaged from each lib. of
hydrogen gas*, - - . . 295.58950

Caloric difengaged from each lib. of
oxygen gas, - - . 52.16280

£aloric difengaged during the forma-
tion of each pound of water, - 44.33840

Caloric retained by each lib. of oxy-
gen after combufiion with hydro-
gen. 14-50386

Caloric retained by each lib. of wa-
ter, at the temperature of 31", 12.-32823

0/tbe Formation o/Nilrif Acid.

OF CHEMISTRY. 157

which it poflfefied in the date of gas. It is cer-
tainly poffible to determine the quantity of calo-
ric which is difengaged during the combination
of thefc two gafles, and confequently to deter-
mine what quantity remains after the combina-
tion takes place. The firft of thefe quantities
might be afcertained, by making the combination
of the two gaffes in an apparatus furrounded by
ice ; but, as the quantity of caloric difengaged
is very inconiiderable, it would be neceffary to
operate upon a large quantity of the two gaffes,
and in a very troublefome and complicated appa-
ratus. By this confideration, Mr de la Place and
I have hitherto been prevented from making the
attempt. In the mean time, the place of fuch
an experiment may be fupplied by calculations,
the refults of which cannot be very far from
truth.

Mr de la Place and I deflagrated a convenient
quantity of nitre and charcoal in an ice appara-
tus, and found that twelve pounds of ice were
melted by the deflagration of one pound of nitre.
We (hall fee, in the fequel, that one pound of
nitre is compofcd, as under, of

Potafh 7 02. 6 ^ros 5i.84^r/.r-45T5,84^r/.
Dry acid 8 i 21.16 —4700.16

The above quanlitv of dry acid is qompofcd

of,

Oxygen

f53

ELEMENTS

Oxygen 602;. 2 S''°f 66.34 jrj.=3738.34jr/.
Azot I 5 25.82 := 961.S3

By this we find that, during the above defla-
' gratinn, 145-^ gn. of carbon* have fuffered
combuftion, along with 373S.34 jr/. or 6 oz. 3
gros 66.^^£rj. of osygen. Hence, lince 12 libs.
of ice were melted during the combuftion, it fol-
lows, that one pound of oxygen burnt in the
fame manner would have malted 29,5832 iibs.
of ice. To which if we aJd the quantity of
caloric retained by a pound of oxygen, after
combining with carbon to form carbonic acid
gas, which was already afcertaincd to be capable
of melting 29.13844 /j'Aj. of ice, we Ihall have
for the total quantity of caloric remaining in z
pound of oxygen, when combined with nitroue
gas in the nitric acid, 58.72164 ; which is the
number of pounds of ice the caloric remaining in
the oxygen in that ftate is capable of melting.

We have before leen that, in the ftate of oxy-
gen gas, it contained at leaft 66.66667 ; where-
fore it follows that, in combining with azot to
form niiric acid, it only loies 7.94502. Farther
experiments

• From this it appears, that the proporuons ufed by
Mr Lavoi&er were i /i6. or 9216 jrj. of nitrC to i^roi
*T S*"'' "'' *4S"34J'''- "^ charcoal, though he has not
cholcn to mention it in dircA termi.— T.

OF CHEMISTRY. 159

experiments upon this fubjedt are neceflary to
afcertain how far the refuks of this calculation
may agree with direA fa£t. This enormous -
quantity of caloric^ retained by oxygen in its
combination into fiitric acid; explains the caufe*
of the great difengagement of caloric during the
deflagrations of nitre ; or, more ftridUy fpeak-
ing, upon all occafions of the decompolition of
nitric acid.

Of the Combujlion of Wax.

Having examined feveral cafes of limple com-
buftion, I mean now to give a few examples of
a more complex nature. One pound of wax-ta-
per being allowed to burn flowly in an ice ap-
paratus, melted 133.1667 libs, of ice. Accord-
ing to my experiments, as given in the Memoirs
of the Academy for 1784, p. 606, one pound of
wax-taper confifts of 0.8228 libs, of carbon, and
0.1772 libs, of hydrogen.

«

By the foregoing experi-
ments, the above quantity
of carbon ought to melt, 79*39390 libs, of ice ;

And the hydrogen
fliould melt - 52.37605

In all 131.76995 libs.

Thus

l6o ELEMENTS

Thus, we fee that the quantity of caloric
difengaged from a burning taper, is nearly con-
formable to what was obtained by burning fe-
parately a quantity of carbon and hydrogen
equal Co what enters into itq compofition. Thefe
experiments with the taper were feveral times
repeated, fo that I hare reafon to believe them
^curate.

Comhujihn of OHve-Oil.

Wc included a burning lamp, containing a
determinate quantity of olive-oil, in the ordi-
nary apparatus ; and, when the experiment
was finifhed, we afcertained exadly the quan-
titJES of oil confumed. and of ice melted ; the

-OF CHEMISTRY. i6x

buftion J whereas the oil had really mdted
148.88330 libs, which gives an excefsof 10.54554
in the refult of the experiment, above the cal-
culated refult, from data furniflied by former
experiments.

This difference, which is by no means very
confiderable, may arife from errors which are
unavoidable in experiments of this nature, -or
it may be owing to the compofition of oil not
being as yet exactly afcertained : It proves, how-
ever, tbat there is a great agreement between
the refults of our experiments, refpeiling the
combination of caloijCf and thofe which regard
its difengagement.

The following de0der«a flill regain to be
determined; viz. What quantity of caloric is
retMned by oxygen, after combining with me-
tals to convert them into oxyds ; What quanti-
ty is contained by hydrogen, in its different
ftates of exiilence ; and. To afcertain with more
precifion than is hitherto attained, how much
caloric is difengaged during the formation of
water, as there flill reujiain confiderable doubts
.wjtb refped to our prefent determination of this
point, which can only be removed by farther
experiments. We are at prefent occupied with
this inquiry ; and, when thefe feveral points
are well afcertained, which we hope they will
foon be, we ftiall probably be under the necef-
JjT^ of making confiderable corredions upon
X, ipoil

l62

ELEMENTS

mod of the refults of the experiments and cal-
culations in this chapter. 1 did not^ however,
confider this as a fafGcieot reafon for with-hold-
ing fo much as is already known, fron) fuch as
may be inclined to laboui upon the fame fubjed.
It is difficult, in our endeavours to difcover the
principles of a new fcience, to avoid beginning
by conjedure ; and it is rarely poIQble tp attaiii
perfeiaion at the firft fetting out.

OF CHEMISTRY. x6}

CHAP. X.

Of the Combinations of Combujlible Subjlances

with each other.

AS combuftible fubftances in general have
great affinity for oxygen, they ought
likewife to attraft, or tend to combine with,
each other ; ^a funt eadem uni tertio, funt ea-
dem inter fe ; and the axiom is found to be
true. Almoft all the metals, for inftance, are
capable of uniting with each other, and of
forming what are called alloys * in common
language. Mod of thefe, like other chemical
combinations, are fufceptible of feveral degrees
of faturation. The greater number of alloys
are more brittle than the pure metals of which
they are compofed, efpecially when the metals
^oyed together are confiderably different in

L 2 their

* This term alloys which we have from the language
of the arts, {ierves exceedingly well for di(lingui(hing
all the combinations or intimate unions of metals with
each other, and is adopted in oar new nomeqclature fpr
that ptirpofc. — ^A.

X^4

ELEMENTS

their degrcs of fufibility. To this difference
jn fufibility, part of the phenomena attendant
upon aUoyage are owing ; particularly that
property of iron, called by v/orkmcn botpiort.
This kind of iron muft be confidercd as an al-
loy or mixture of pure iron, which is almoft in-
fulible, with a fmall portion of fome other me-
tal, which fufcs ill a uiucli lower degree of lieat :
So long as this alloy remains cold, and both me-
tals are in a foUd ftale, the mixture is mal-
leable ; but when heated to a I'uflicient degree
to liquify the more fulible metal, the particles
of this liquid raetal, which arc interpofed be-
tween the particles of the lulid iron, muft de-
Uroy their continuity, and cccafion the alloy to
become brittle. The alloys of mercury, with the
other metals, have ufually been called amalgams,
and we fee no inconyenitnce from continuing the
ufe of that terra.

Sulphuir, phofphonis, and carbon, readily
unite with metals. Combinations of fulphur
with metals are ufually narked /ijM(f.r. Their
combinations with phofphorus and carbon arc
either not yet named, or have received new
names only of late ; wherefore we have not
icruplcd to change them according to qur
principles. The combinations of metal and
lulphur we cuWfulphurets, thole Mith phofpho-
rtis pbofpbards, and thofe formed w ith carbon
csrbiireii *.

I

OF CHEMISTRY. i5j

carburets *. Thefe denominations are extend-
ed to all the combinations into wLich the above
three fubllances enter, without being previouf-
\y oxygenated. Thus, the combination of ful-
phiir with potafli, or fixed vegetable alkali, is
cAl^A fulpburet of pola/b i that which it forms
with ammoniac, or volatile alkali, is termed yi//-
pburet of ammoniac.

Hydrogen is likcwife capable of combining'
with many combuftible fubftances : In the itute
of gas, it diflblves carbon, fulphur, phofpliorus,
and feveral metals i we diflinguilh thefe combi-
nations by the terms carbonated hydrogen gits,
fulpburated hydrogen gas, and pbofphorated by-
drogengas. The fulphurated hydrogen gas wai
called hepatic air by former chemitls ; or fretid
air from fulpbur, by Mr Scheclc : The virtues
of feveral mineral waters, and the fcctid Imdl
of animal excrements, chiefly arife from the pre.
fence of this gas. The phofporated hydrogen
gas is remarkable for the property, ditcovered
L3 by

" In the French tiomenclalure, theli: compoundi are
n»,rwi fulphur IS, phoffhurts, ;uid carhures ; but, ihongli
(hefc tcTiDi may be fufficiently diftingiiilhabli: from fuuj}'' e.
phnfpborf, and rarbont, they arc not, efpecialJy tlic (wo
lirft, dillinft enough in EngliHi -, I have thtrefore cho-
fen to borrow the new Englilh icrms in the text, frnm
tbcljatin edition of ihe new norocnclaiurc, when; ibej
»tc called refpeflively fulphuretlum, phofphorrlium, and
buret turn. — T.

t66

ELEMENTS

hy Mr Gcngembre, of taking fire fpontaneonf-
}y upon getting into eontaiA with atmorpheiic
ait, or, what anlwers better, with oxygen gas :
This gas has a ftrong flavour, refembling that
of putrid fiHi ; and it is very ptobable that the
phofphorcfcent quality of filh, in the ftate of
putrefaction, arifes from the efcape of this fpe-
cies of gas. When hydrogen and carbon aie
Combined together, without the intervention
of caloric to bring the hydrogen into the ftate
of gas, they form oil^ which is either fixed of
volatile, according to the proportions of hy-
drogen and carbon in its compofition *. The
chief difference between fi&ed or fat oils drawn
from vegetables by expreffion, and volatile or

Ot CHEMISTRY. 167

In the Memoirs of the Academy for 1 784,
p. 593. I gate an account of my ezperimema
upoD the coffipolition of oil and alkohol, by the
union of hydrogen with carbon, and of theii'
combination with oxygen. By thefe experi-
ments, it appears that fixed oils combine with
oxygen during combuftion, and are thereby
converted into water and carbonic acid. By
means of ealcnlatton, applied to the produces
of thefe experiments, we find that fixed oil
is compofed of 21 pans, by weight, of hydro-
gen combined with 79 parts of carbon. Per-
haps thefolid fubftances of an oily nature, fuch
as wax, contain a proportion of oxygen, to
which they owe their ftate of folidity. I am
at prefcnt engaged in a ferics of experiments,
which I hope will throw great light on this fub-

It is worthy of being examined, whether hy-
drogen in its concrete ftate, uncombined with
caloric, be fufceptible of combination with ful-
pbur, phofphorus, and the metals. There is
nothing that we know of, which, a priori,
{hould render thefe combinations impoQibIc ;
for combuftible bodies being in general fuC*
ceptible of combination with each other, there
is no evident reafon for hydrogen being an ex-
ception to the rule : However, no direct ex-
periment as yet eftabliihcs either the poffihi-
Mty or impoffibility of this union. Iron and
. L 4 3-inc

ELEMENTS

CHAP. XI.

Obferuationi upon Oxyds and Adds wub com-
pound Bafes — and on the Cotnpofition of Ani-
mal and Vegetable Suhjlances.

WE have, in Chap. V. and VIII. examined
the ptoduifls refuliing from the combuf-
tion of the four fimple combuflible fuhftances,
fulphur, phofphonis, carbon, and hydrogen : We
have flitwn. in Chap. X. that the fimple combuf-

OF CHEMISTRY. 171

It was long ago well known, that, when mu«
riatic and nitric acids were mixed together, a
compound acid was formed, having properties
quite diftinA from thofe of either of the acids
taken feparately. This acid was called aqua
regia^ from its moft celebrated property of dif-
folving gold, called king of metals by the alchy-
mifts. Mr BerthoIIet has diftinftly proved, that
the peculiar properties of this acid arife from the
combined adion of its two acidifiable bafes, and,
for this reafon, we have judged it neceffary to
diftinguifh it by an appropriate name j that of
nitro-muriatic acid appears extremely applicable,
from its expreffing the nature of the two fub-
ftances which enter into its compoiition.

This phenomenon, of a double bafe in one
acid, which had formerly been obferved only in
the nitro-muriatic acid, occurs continually in
the vegetable kingdom ; in which afimple acid,
or one poflefled of a fingfe acidifiable bafe, is
very rarely found. Almoft all the acids pro-
curable from this kingdom have bafes com-«
pofed of carbon and hydrogen, ot of carbon,
hydrogen, and phofphorus, combined with more
or lefs oxygen. All thefe bafes, whether dou-
ble or triple, are likewife formed into oxyds^
having lefs oxygen than is neceffary to give
them the properties of acids. The acids and
oxyds from the animal kingdom are ftill more
compound, as their bafes generally conlifl of a

coinbination

172

ELEMENTS

combioation of carbon, phofphonis, hydrogen,
and azot

As it is but of late that I have acquired any
clear and diftinA notions c^ thefe fubftances, I
Ihall not in this place enlarge much upon the
fubjeft, which I mean to treat of very fully in
fome memoirs 1 am preparing to lay before the
Academy. Moft of my experirhenta are al-
ready peformed ; but, to be able to give exaffc
reports of the refulting quantities, it is neceflary
that .they be carefully repeated, and increafed
in number : Wherefore, I ihall only give a fliort
enumeration of the vegetable and animal acids
and oxyds, and terminate this article by a few
refleAions upon the compofition of vegetable

" »abl(> acids ai

OF CHEMISTRY.

^73

table acids and oxyds, by ufing the names of
the two fubftances which compofe their bafes :
They would thus become hydro-carbonous a-
eids and oxyds. In this way we might indicate
which of their elements exited in excefs, with-
out circumlocution, after the mannet ufed by
Mr Rouelle for naming the vegetable extrafls:
He calls thefe extraflo-refinous, when the ex-
traftive matter prevails in their compoGtion,
and refino-extrai^live, when they contain a
larger proportion of refinous matter. Follow-
ing that plan, and by varying the terminations
according to the formerly eftablilhed rules of
our nomenclature, we have the following deno-
minations : Hydro-carbonous, hydro-carbonic,
carbono-hydrous, and car bono- hydric, oxyds.
And, for the acids : Hydro-carbonous, hydro-
catbonic, oxygenated hydro-carbonic ; carbono-
hydrous, carbon 0- hydric, and oxygenated car-
bono- hydric.

It is probable, that the above terms would
fuffice for indicating all the varieties in nature,
and that, in proportion as the vegetable acids
become well underftood, they will naturally
arrange theralelves under thefe denominations.
But, though we know the elements of which
-thefe are compofed, we are as yet ignorant of
%he proportions of thefe ingredients, and are Hill
fir from being able to clafs them in the above
pethodicul maimer j wherefore, we have de-
termined

174

ELEMENTS

tcrmined to retain the old names pt'OTifionally,
I am fomewbat farther advanced in this inqui-
ry than at the time of publiAiing our conjunct
eflay upon chemical nomenclature; yet it would
be improper to draw decided confequences from
experiments not yet fufRciently prccife : Though
I acknowledge that this part of chcmiftry ftill
remains in fomc degree obfcure, I muft exprefa
my expedatious of its being very foon elucida-
ted.

I am ftill more forcibly neceflitated to follow
the fame plan in naming the acids, which have
three or four elements combined in their bafes ;
of thefe we have a confiderable number from
the animal kingdom, and fome even from ve-

or CHEMISTRY.

«75

pronounce and to be remembered. Belides,
this part of cbemiftry being llill far from that
accuracy it mud foon attain, the perfedion of
tbe fcicncc ought certainly to precede that of
its language \ and we mufl ftill, for Tome
time, retain the old names for the animal
oxyds and acids. We hare only ventured to
make a few flight modifications of thefe names,
by changing the tenrnnation into oaj, when we
have reafoo to fuppofe the bafe to be in excefs,
and into tV, when we fufped that oxygen pre-
dominates.

The following are all the vegetable acids hi^
therto known :

1. Acetous acid.

2. Acetic acid.

3. Oxalic acid.

4. Tartarous acid.

8. Pyro-mucous acid.

9. Fyro-lignous acid.

10. Gallic acid.

1 1 . Benzoic add.

5. Pyro-tartarous acid. 12. Camphoric acid.

6. Citric acid. 13. Succinic acid.
■J. Malic acid.

Though all thefe acids, as has been already
&id, are chiefly, and almofl entirely compofed
of hydrogen, carbon, and oxygen, yet proper-
ly fpeaking, they contain neither water, carbo-
nic acid, nor oil, but only the elements nccef-
fary for forming thefe fubftances. The power
of affinity reciprocally exerted by the hydrogen,
parbon, and oxvgen, in thefe acids, is in a ftate

of

176

ELEMENTS

t:f equilibrium, that is only capable of exifting
in the ordinary temperature of the atmofphere :
For, when they are heated but a very little a-
bove the temperature of boiling water, this equi-
librium'is deftroyed; part of the oxygen and hy-
drogen unite, and form water j part of the car-
bon and hydrogen combine into oil ; part of the
.carbon and osygeo unite to form carbonic acid ;
and, laftly, there generally remains a fmdl por-
tion of carbon, which, being in excefs with re-
fyt& to the other ingredients, is left free. I
mean to explain this fubjeA fomeivhat further in
the fucceeding chapter.

The oxyds of the animal kingdom are hither-
to lefs known than thofe from the vegetable king- "

OF CHEMISTRY.

^11

The connedlion between the conftituent ele-
ments of the animal oxyds and acids is not
more permanent than in thoTe from the vege-
table kingdom , a!> a fmall increafe of tempera-
ture is fufficient to overturn the equilibrium. I
hope to render this fubjeft more diftinft in the
following chapter than has been done hitherto.

M

CHAP.

178

ELEMENTS

CHAP. XII.

Of the Decompajttion of Vesttable and Animal
Subjlances by tbe A^ion of Fire.

BEFORE we can thoroughly comprehend
what takes place during the decompofi-
tion of vegetable fubftances by fire, we muft
take into consideration the nature of the ele-
ments which enter into their compofition, and
the different affinities which the particles of
thefe elements exert upon each other, and the
affinity which caloric poflefles with each of

OF CHEMISTRY. 179

^vitli hydrogen dr with carbon, has a much
ftronger affinity with carbon, when at the red
heat *, and then Unites with it to form carbonic
acid.

Although we are far from being able to ap-
preciate all thefe powers of affinity, or to exprefs
their proportional energy by numbers, we are
certain, that, however variable they may be,
when confidered in relation to the quantity of
caloric with which they are combined^ they are
all nearly in equilibrium in the ufual tempera-
ture of the atmofphere ; hence vegetables nei-
ther contain oilf, water, nor carbonic acid,
though they contain all the elements of thefe
fubilances. The hydrogen is not combined
particularly with the oxygen nor with the car-

M 2 bon ;

* Though this term, red heat, does not indicite any ab-
Iblutely determinate degree of temperature, I (hall ufe it
fbmetimes to exprefs a temperature coniiderabJy above
that of boiling water. — A.

^ I muft be undetftood here to fpeak of vegetables redu-
ced to a perfeffly dry (late ; and, with refprft to oil, 1 do
Act mean that which is procured by expreflion either in
the cold, Or in a temperature not exceeding that of boiling
Water; 1 only allude to the empyreumatic oil procurcrd
by diftillation with a naked fire, in heat fuperior to the
temperature of boiling water ; which is the only oil de-
dared to be produced by the operation of fire. What I
have publiihed upon this fubje£l in the Memoirs of die
Academy for 1786 may be confulted.— A.

ELEMENTS

bon ; and reciprocally : The particles of tliefc
three fubftances form a triple combination, which
remains in equilibrium, while undillurbed by
caloric ; but a very flight increafe of tempera-
ture is fufficient to- overturn this llrudure of
combination.

If the increaled temperature to which the
vegetable is expofed does not exceed the heat of
boiling water, one part of the hydrogen com-
bines with the oxygen, and forms water ; the
reft of the hydrogen combines with a part of
the carbon, and forms volatile oil ; while the
remainder of the carbon, being fet free from its
combination with the other elements *, remains
fixed in the bottom 6f the dilliiling vcflel.

When, on the contrary, wc employ a red

OF CHEMISTRY. iSr

hydrogen gas*. In this high temperature, ei-
ther no oil is formed, or if any has been produ-
ced during the lower temperature, at the begin-
ning of the experiment, it is decompofed by the
a£tion of the red heat. Thus the dccompofltion
of vegetable matter, under a high temperature,
IB produced by the action of double and triple
affinities ; while the carbon attrafls the oxygen,
onpurpofe to form carbonic acid, the caloric at-
tracts the hydrogen, and converts it into hydro-
gen gas.

The diftillation of every fpecies of vegetable
fubftance confirms the truth of this theory, if
we can give that name to a fimple relation of
&&%. When fugar is fubmitted to didillation,
fo long as wc only employ a heat but a little
below that of boiling water, it only lofes its
water of cryftallization, it ftiU remains fugar,
and retains all its properties; but, immediately
upon raifing the heat only a little above that
degree, it becomes blackened, a part of the car-
bon feparates from the combination, water
llightly acidulated paiTes over, accompanied by
M3 a

* The hydrogen gas, produced in this way, is not pure,
bot holds a con£derable portion of carbon in folution: It
U carbonated hydrogen gaj, called, in the old chemical
luiguagCT heavy inflammable air. — T.

j8»

ELEMENTS

a little oil, and the charcoal * which remuns in
the retort is nearly a third part of the original
weight of the fugar.

The operation of affinities which takes places
during the decompofition, by fire, of vegetables
which contain azot, fuch as the cruciferous
plants, and of thofe containing phofphorus, is
more complicated ; ' but. as tbefe fubftances on-
ly enter into the compofition of vegetables ii^
very fmall quantities, they only, apparently,
produce flight changes upon the produfSs of dif-
tillation. Ihe phofphorus feems to combine
with carbon, and, acquiring fixity from that u-
nion, remains behind in the retort ; while the
azot, combining with a part of the hydrogen.

OF CHEMISTRY. 183

givealmolt the fame produds in diftillation ;
with this difference, that, as they contain a
greater quantity of hydrogen and azot, they
produce more oil and more ammoniac. I (hall
only produce one &£t as a proof of the exadl«
nefs with which this theory explains all the phe-
nomena that occur during the diftillation of
aaimal fubftances ; which is the re£tification,
and total decompofition, of volatile animal oil,
commonly known by the name of Dippels' oil.
When thefc oils are procured by a firft diftilla-
tion in a naked fire they are brown, from con-
taining a little carbon, almoft in a free ftate ;
but they become quite colourlefs by redifica-
tion : Even in this ftate, the carbon in their
coi?[ipo(ition has fo flight a.connedion with the
other elements as to feparate from them by
mere expofure to the air. If we put a quanti-
ty of this animal oil, well redified, and confe-
quently clear, limpid, and tranfparent, into a
bell-glafs filled with oxgen gas over mercury,
in a Ihort time the gas is much diminifhed, be-
ing abforbed by the oil ; the oxygen combining
with the hydrogen of the oil forms water, which
finks to the bottom ; at the fame time the car-
bon, which was combined with the hydrogen,
being fet free, manifefts itfelf by rendering the
oil black. Hence the only way of preferving
thefc oils colourlefs and tranfparent, is by keep-
ing them in bottles perfedly full an4 accurate-

M4 iy

1 84

ELEMENTS

ly corked, to hinder the contad^ of air, vhich
always difcolours them.

Succeflive rei5tifications of this oil furnifli aiu
other phenomenon confirming our theory. In
each diftillation a fmall quantity of charcoal re-
mains in the retort ; and a little water is form-
ed, by the union of the oxygen contained in
the air of the diftilling vefTek with the hydro-
gen of the oil. As this takes place in each fuc-
ceflive diftillation, if we make ufe of large vef-
fels and a confiderahle degree of heat, we at laft
decompofe the whole of the oil, and change it
entirely into water and charco^ When vrlt
ufe fmall veHels, and efpecially when we em-
ploy a Oow fire, or a degree of heat only a little

OF CHEMISTRY. 185

CHAP. XIII.

Of' the Dicompojtiion of Vegetable Oxyds by the

Vinous Fermentation.

THE manner in which wine, cyder, mead^
and all the liquors formed hj the fpiri-
tous fermentation, are produced, is well known
to every one. The juice of grapes or of apples
heing exprefled, and the latter being diluted with
water, they are put into large vats, which are
kept in a temperature of at lead 54.5'' of the
thermometer. A rapid inteftine motion, or fer-
mentation, very foon takes places, numerous
globules form in the liquid and burft at the fur«
face ; when the ^fermentation is at its height,
the quantity of gas difengaged is fo great as to
make the liquor appear as if boiling violently
over a fire. When this gas is carefully gather-
ed, it is found to be carbonic acid perfedlly
pure *, and free from admixture with any other
fpecies of air or gas.

When

♦ This affertion of the perfeA purity of carbonic acid
gas, difeogaged during the vinous fermentation, muft be
taken with fome allowance ^ for it almoft alwajs, I believe

cooftantly.

286

ELEMENTS

When the fenneDtation is completed, the
juice of grapes is chaDged, from being fweet and
full of fugar, into a vinous liquor, which no
longer contains any fugar, and &om which we
procure by diftillation an inflammable liquor,
known in commerce under the name of Spirit
of Wine. As this liquor is produced by the fer-
roentation of any faccharine matter whatever
diluted with water, it muft have been contrary
to the principles of out nomenclature to call
it fpirit of wine rather than fpirit of cyder,
or of fermented fugar ; wherefore, we have a-
dopted a more general term, and the Arabic
word alkobol feems extremely proper for the
purpofe.

OF CHEMISTRY. 187

We may lay it down as an inconteftible
axiom, that, in all the operations of art and
nature, nothing is created ; an equal quantity
of matter exiils both before and after the expe*
riment; the quality and quantity of the ele*>
ments remain precifely the fame : and nothing
takes place beyond changes and modifications
in the combinations of thefe elements. Upon
this principle, the whole art of performing che-
mical experiments depends : We muflT always
fuppofe an exa<% equality between the elements
of the body examined, and thofe of the products
of its analyfis.

Hence, fince from muft of grapes we procure
alkohol and carbonic acid, I have undoubted
right to fuppofe that muft confifts of carbonic
acid and of alkohol*. From thefe premifes, we
have two methods of afcertaining what pafles
during vinous fermentation : Either by deter-
mining the nature of, and the elements which
compofe, the fermentable fubftances ; or by ac«
curately examining the produces refulting from
fermentation ; and it is evident that the know-
ledge

* In this afl*ertion the confeqaences do not dri&ly fol*
low from the premifes y bccaufe from the muii of grapes
we procure carbonic acid and alkohol, it is a ncceflary con-
fequence that the original mufl contains the conflituenC
elements of carbonic acid and of alkohol, but not that
^zk produfls of fcrmemation are already formed.— T*

]88

ELEMENTS

ledge of either of thefc muft lead to accurate
conclufions concerning the nature and compo-
fition of the other. From thefe confiderations,
it became necelTary accurately to determine the
conftituent elements of the fermentable fubftan-
ces ; and, for this purpofe, I did not make ufe
of the compound juices of fruits, the rigorous
anal/fis of which is perhaps impoOible, but made
choice of fugar, which is eafily analyfed, and
the nature of which I have already explained.
This fubtlance is a true vegetable oxyd with
two baf^s, compofed of hydrogen and carbon,
brought to the ftatc of an oxyd, by means of a .
certain proportion of oxygen ; and thefe three
elements are combined in fuch a way, that a

OF CHEMISTRY. 189

tion *. This is accomplilhed by means of a
little yeaft from beer ; and, when the feriifenta-
tion is once excited, it continues of itfelf until
completed. I fhall, in another place, give an ac-
count of the efieAi of yeaft, and other ferments,
upon fermentable fubftances. I have ufually
employed 10 libs, of yeaft, in the ftate of pafte,
for each 100 libr. of fugar, with as much water
as is four times the weight of the fugar. I fhall
give the refults of my experiments exadly as
they were obtained, preferving even the iradioas
produced by calculation.

* This is not firidly true ; for, ttpeciaUy in warm wea-
thers, all fympa arc apt to run into fermentation, unlefii
very rich of the fugar, and carefully preferved. At the
£une time, this fpontancous fermentation is not fo regular
as when affifted by yealt, and 'a apt to become in part
icetoDi, before completing Uie vinous proccfs.— T.

19°

ELEMENT^

Table I. Materials of Fermentation*.

Water - _ „

Sugar - - -

Yeaft. in pafte, 10 /lif. f Water

GOmpoled of i Dry Yeaft

His.

4C0.

ICQ.

7.2191493
1.7608507

Table II. Conftituent Element! of the Materialx
of Fermentation.

407.3391493 libi, of water, C Hydrogen 61.0858734
compofed of (_ Oxygta 346.1532769

lOB libs, liigar, compofed

J Hydrogen 8.
Oxygen 64.

(, Carbon 18.

r Hydrogen .2900716

S.760S507 llbt. t^&xj yeall, J Oiygen 1.6437457

conpoled of 7 Ca[1>on ■7^7^5<9

LAzot -oiW^^i

ToUl weight iio. libs.

Table

* The quantities in the original are exprefled in tfae
common divifions of the Paris pound, but. to render the
refults more generally ufeful to the Englifli reader, they
are all here reduced to dcumaJ$, which anfwei equally
foi iDjr puuod.— T.

T^Cl .^..^

OF CHEMISTRY.

191

Table III. Recapitulation of thefe Elements.

rof the water
of the water
Sii ID the yeaft
Q I of the fugar
t of the dry yeaft

p f of the water
jSo I of the water
in the .yeaft
the fugar
the dry yeaft

A g Cof the fugar
^3 J Lot the yeaft

Azot of the yeaft

libs.
340-

}libs.
411.7970226

€0.

1.0858724 V 69.3759440

8.
0.2900716.

28.
o

0.0393815

In all $10. libs.

Having thus accurately determined the na-
ture and quantity of the conftituent elements
of the materials fubmitted to fermentation, we
have next to examine the products refulting
from that procefs. For this purpofe, I placed
the above 510 libs, of fermentable liquor in a
proper • apparatus, by means of which I could
accurately determine the quantity and quality
of gas difengaged during the fermentation, and

could

* The above apparatus b defcribed in the Third Part.
•A.

Ipl

ELEMENTS

could even weigh every one of the produfls fe-
parately, at any pexiod of the procefs I judged
proper.

An hour or two after the fubftances are mixed
together, efpecially if they are kept in a tem-
perature of from 66° to 73= of the thermome-
ter, the firft marks of fermentation commence ;
the liquor turns thick and frothy, little globules
of air are difengaged, which rife and burft at
the furface ; the quantity of thefe globules
quickly increafes, and there is a rapid and abun-
dant produdion of very pure carbonic acid, ac-
companied with a fcum, which is the yeaft fe-
parating ^from the mixture. After feme days,
lefs or more according to the degree of heat,
the inteftine motion and difcn

OF CHEMISTRY.

Table IV. Product of Fermentation.

35.345 St i6££t. of carbo-
nic tdd, com* 4

pOUQ 01

Oiygen .

Carbon -

35.4490017
9.8 -"

408.9780816 Uhi. of water, C Oxygen
compolcd of \ Hydrogen

57.7016059 Shi. of dry al-
kohol, CODQpO-
frdof

- 347-63»40«9
61.3466797

' Oiygen, combined

with hydrogen 31.3897570

Hydrogen, combi-
ned with oxygen 5.5393880

Hydrogen, combi-
ned with carbon 4.0390625

Carbon, combined

with hydrogen 16.7333984

3.5000000 i!ib. oE dry ace- rHydragen
tons acid, com- J Oxygen
poled of I. Carbon

4.0940755 /tlSi.ofrefidunm rHydrogen
of fugar, com- < Oxygen
pofedof {.Carbon

r Hydrogen
1.3804*54 /ifo.of dryyeaftfj Oxygen
composed of ] Caibon

lAzot

5 10 Sbu

0.1563500
1.7187500

0.6350000

0.3475835
3.6301173
«14637S8

o-»45o738
0.8S18317
0.3938802
0.0196397

510/i'i;.

fpfi

ELEMENTS

two and tvo together, tQ form water and carbo-
nic acid.

The effects of the rinous feimeptation upon
fugar is thus reduced to the mere reparation of
its elements ipto two portions ; one part is oxy-
genated at the expence of -the other, fo as to
form carbonic acid, while the other part,, being
difoxygenated in favour of the former, is con-
verted into the combuftible fubftance called al-
Jtohol J therefore, if it wefe poffible to re-unite
alkohol and carbonic acid tc^ther, we ought
to form fugar. It is evident that tbe carbon
and hydrogen in the alkoho} do not exift in the
ftate of oil, but that they are combined with a
portion of oxygen, which renders them mifd-

OF CHEMtSTRY. 197

jiToper for compoficg it. It may be readily con-
ceived, that it muft have coft me a good deal to
abandon my firft notions ; but by feveral years
refledion, and after a great number of experi-
ments and obfervations upon vegetable fubftan-^
ces, I have fixed my ideas as above.

I fhall finilh what I have to fay upon vinous
fermentation, by obferviog, that it fumilhes us
with the means of analyfing fugar and every
vegetable fermentable matter. We may con«
fider the fubftances fubmitted to fermentation^
and the produds refulting from that operation^
as forming an algebraic equation ; and, by fuc*
ceflively fuppofing each of the elements in this
equation unknown, we can calculate their values
in fucceffion, and thus verify our experiments by
calculation, and our calculations by experiment,
reciprocally. I have often fuccefsfuUy employ-
ed this method for correAing the firft refults
of my experiments, and to diredl me in the pro«>
per road for repeating them to advantage. I
have explained myfelf more at large upon this
fubjed, in a Memoir upon vinous fermentation
already prefented to the Academy, ^nd which
kriU fpeedily be publifhed.

N3 CHAP.

198

ELEMENTS

CHAP. XIV.

Of the Putrrfa^ve Fermentation.

THE pbeDomena of putrefai^ion are caufed^
like thoCe of vinous fermentatioo, by the
operation of extremely complicated affinities.
The conftituent elements, of the bodies which
aie fubmitted to.thia procels, ceafe to continue
ID equilibrium, in their original tbceefbld com-
bination, and form themfelves anew into binary.
combinations*, or compounds confiftlng of two

of CHEMlSTRt, 1^

terials have been mixed with a fufficient quan-
tity of water, nothing remains but the earth of
the vegetable, mixed with si fmall portion of
charcoal and iron. Thus^ putrefadtion is no^
thing more than a complete analyfis of vege-
table fubftance ; during which the whole of the
conftituent elements is difengaged in form of gas,
/•xcept the earth, which remains in the ftate of
mould *•

Such is the refult of putrefadtion, when the
fubftances fubmitted to it contain only oxygen,
hydrogen, carbon, and a little earth. But
this cafe is rare, and thefe fubftances putrify
imperfe^ly and with difficulty, and require a
confiderable time to complete their putrefac-
tion. It is otherwife with fubftances containing
azot, which indeed exifts in all animal matters,
and ^ven in a confiderable number of vegetable
fubftances. This additional element is remark-
ably favourable to putrefadtion ; and for this
reafon, animal matter is mixed with vegetable,
when the putrefadtion of thefe is wilhed to be
haftened. The whole art of forming compofts
and dunghills, for the purpofes of agriculture,
confifts in the proper application of this admix-
ture.

N4 The

* In the Third Part will be given the defcription of an
apparatus proper for being ufed in experiments of this
Uad.-«-A«

ELEMENTS

The addition of azot to the materials of putre-
faftion not only accelerates the procefs, but that
clement lilcewife coinbioes with part of the
hydrogen, and forms a new fubftance, called
volatile alAeli, of ammoniac. The refults ob-
tained by analyfing animal matters, by different
procefies, leave no room for doubt with regard
to the confUtuent elements of ammoniac i for,,
whenever the azot has been ptevioufly feparated
from thefe fubftances, no ammoniac is produced,
and in all cafes they fiirnifh ammoniac only in
proportion to the azot they contain. This com-
pofition of ammoniac is likcwife fully proved by
Mr BerthoUet, in the Memoirs of the Academy
for 1781, p. 316. where he gives a variety of

OF CHEMISTRY. 2ci

the phofphorated fmells exadly like putrid fifli.
Ammoniac has likewife a peculiar odour, not
lefs penetrating or lefs di&greeable than thefc
other gaffes. From the mixture of thefe differ-
ent flavours proceeds the fetor which always ac-
companies the putrefadion of animal fubitan-
ces. Sometimes the ammoniac predominates,
which is eafily perceived by its Iharpnefs upon
the eyes ; fometimes, as in feculent matters, the
fulphurated gas is moft prevalent ; and fomc-
times, as in putrid herrings, the phofphorated
hydrogen gas is moft abundant.

I long fuppofed that nothing could derange
or interrupt the courfe of putrefadion ; but
Mr Fourcroy and Mr Thourct have obferved
fome peculiar phenomena in dead bodies, bu-
ried at a certain depth, and preferved to a cer-
tain degree, from contad with air -, having
found the mufcular fielh frequently converted
into true animal &t *. This muft have arifen
from the difengagement, by fome unknown
caufe, of the azot, naturally contained in the
animal fuhftance, leaving only the hydrogen
and carbon remaining, which are the elements
proper for producing fat or oiL This obferva-

tion,

* This proce& has been lately imitated aititicially ; and
the fatty fubftancc, exa^Iy fimilar in all rcfpcfe to Sper-
macetiy can be readily made from the flefh or mufcular
parts of all animal bodies.— -T.

ELEMEiJTS

tion, on die poflibility of converting animal fub-
llanccs into fat, may feme time or other lead to
difcovcrics of great importance to focicty. The
fxces of animals, and other excrementitious
matters, are chiefly compofed of carbon and
hydrogen, and approach conliderably to the na-
ture of oil, of which they fuFoifh a conliderable
quantity by diftillation with a naked Gre ; but the
intolerable fcetor, which accompanies all the pro-
duAs of thefe fubftances, prevents our expeding
that, at leafl for a long time, they can be render-
ed ufeful in any other way than as manures.

I have only given conjeftural approximations
in this chapter, upon the compofltion of animal
fubftances, which is hitherto imperfeAly under-

OF CHEMISTRY. 303

CHAP. XV.

Of the Acetous Fermentation.

THE acetous fermentatioD is oothiog more
than the acidification or oxygenation of
wine *, produced in the open air, by means of
the absorption of oxygen. The refulting acid
is the acetous acid, commonly called Vinegar,
which is compofed of hydrogen and carbon u-
nited together in proportions not yet afcertain-
ed, and changed into the acid flate by oxygen.
As vinegar is an acid, we might conclude from
anal<^y, that it contains oxygen, but this is
put beyond doubt by direA experiments : In
the firft place, we cannot change wine into vine-
gar without the contadl of air containing oxy-
gen ; fecondly, this procefs is accompanied by
a diminution of the volume of the air in which
it is carried on, from the abforption of its oxy-
gen ; and thirdly, wine may be changed into
vinegar, by any other means of oxygenation.

Independent

■ The wend Wine, la this chapter, is uCed to fignify ihe
liquor produced by ttie vinous fermeniation, whatever ve-
^nble fubfiance may have beea ufed for obtainiog it. — T.

ELEMENTS

Independent of the proofs which thefe fads
favnifh of the acetous acid being produced by
the oxygenation of wine, an expcrimeoi made
by Mr Chaptel, ProfelTor of Chcmitlry at Mont-
pellier, gives a diilindl view of what takes- place
in this procefs. He impregnated foine water
with about its own bulk of carbonic acid from
fermenting beer, and placed this water in a
cellar, in veflels communicating with the 'air,
and in a (hort time the whole was converted in-
to acetous acid. This carbonic acid gas, pro-
cured from beer vats in fermentation, is not
perfedtly pure, but contains a great quantity of
alkohol in folution, wherefore water impregna-
ted with it contains all the materials necefiary
for forming the acetous acid. The alkohol fur-
nifhes hydrogen and one portion of carbon ; the
carbonic acid fumifhes oxygen and the reit of
the carbon ; and the air of the atmofphere fur-
niOies the reft of the oxygen neceffary for chan-
ging the mixture into acetous acid. From this
obfervation it follows, that nothing but hydro-
gen is wanting to convert carbonic acid into ace-
tous acid ; or, more generally, that, by means
of hydrogen, and according to the degree of
oxygenation, carbonic acid may be changed into
all the vegetable acids ; and, on the contrary,
that, by depriving any of the vegetable acids of
their hydrogen, they may be converted into car-
bonic acid.

Although

OF CHEMISTRY.

205

Although the principal fadts relating to the
acetous acid are well known, yet numerical pre-
cifion is dill wanting, until furnifhed by more
exad experiments than any hitherto perform-
ed ; wherefore I (hall not enlarge any farther
Upon the fubjed. It is fufficiently fhewn by
what has been faid, that the conftitution of ^
the vegetable acids and oxyds is exaftly con-
formable to the formation of vinegar ; but far-
ther experiments are neceflary to teach us the
proportion of the conftituent elements in all
thefe acids and oxyds. We may eafily per-
ceive, however, that this part of chemiftry, like
all the reft of its divifions, makes rapid progrefs
towards perfeftion, and that it is already ren-
dered greatly more fimple than was formerly be-
lieved.

• •#• > -

V :■■'■' -■

CHAP.

ELEMENTS

CHAP. XVI.

Of the Formation of Neutral Salts, and of tbeir
different Bafei.

WE have juft feen, that all the oxyds and
acids from the animal and vegetable
kingdoms are formed from a fmall number of
llmple elements, by means of combination with
oxygen, or at leaft from fuch bodies as have not
hitherto been fufceptibic of decompofition, and
which muft therefore beconfidcred as fimple fub-

OF CHEMISTRY. 307

dofe of oxygen employed for oxydating or aci-
difying them. We ftiall find the means no lefs
fimple and diverfified, and as abundantly pro-
du£tive of forms and qualities, in the order of
bodies we are now about to treat of.

Acidifiable fubftances, by combining with
oxygen, and their confequent converfion into
acids, acquire a great fufceptibiltty for farther
combination ; they become capable of uniting
with alkaline, earthy, and metallic bodies, by
which means neutral falts are formed. Acids
may therefore be confidered as Xxu^falifying prin-
ciples, and the fubftances with which they unite
to form neutral falts may be called J'alifiable
bafes : The nature of the union which thefe two
principles form with each other is meant as the
fubjeit of the prefent chapter.

The foregoing view of the acids prevents
them , from being confidered as falls, though
they are poflefled of many of the principal pro-
perties of faline bodies, as folubility in watei^
&c. It is already obferved, that they are the
refults of a firft order of combination, being
compofed of two fimple elements, or at leaft of
elements which aft as if they were fimple, and
they may therefore be ranked, to ufe the lan-
guage of Stahl, in the order of mixti. The
neutral falts, on the contrary, arc of a feconda-
ry order of combination, being formed by the
pnion of two mtxis with each other, and may
therefore

20S

ELEMENTS

therefore be termed compoiindr. Hence I fliall
not arrange the alkalies * or earths in the clafs
of falts, to which I allot only fuch as are com-
pofed of an oxygenated fubftance united to a fa-
li£able bafe.

I have already enlarged fulficiently upon the
formation of acids in the preceding chapter, and
fhall not add any thing farther upon that fub-
}t£t ; but having as yet taken no notice of the
faliBable bafes which are capable of uniting
with them to form neutral falts, I mean, in this
chapter, to give an account of the nature and
origin of each of thefe bafes. Thefe are potafli^
foda, ammoniac, lime, magnefia, barytes, argillf,
and all the metallic bodies.

OF CttEMISTRT. aop

io diftilling vdTels, its component elements, oxy-
gen, hydcogcD, and carbon, which formed a
threefold combination in a Hate of equilibrium,
unite two and two, in obedience to afBnities
which a6t conformable to the degree of heat
employed. Thus, at the firll application of the
fire, whenever the heat produced exceeds the
temperature of boiling water, part of the oxy-
gen 9qd hydrogeq unite to form water ; foon
after, th? reft of the hydrogen and pare of the
carhoq coipbine into oil ; and, lallly, when the
fire is puflfed to the red heat, the oil and wa-
iter, which had been formed in the early part
of tl^e procefs, become again decompofed, the
oxygen and part of the carbon unite to form
Qubpnic acid, a large quantity of hydrogen gas
is fet free, and nothing but charcoal remains in
the retort.

A great part of thefe phenomena occur du-
fing the cQmliuft^op of vegetables in the open
ur ; but, in this cafe, the prefence of the air
introduces three new fubftances, the oxygen
sad azot of the air, aAd caloric, and, of thefe,
two at leaft produce conCderable changes in the
refvlta of the operation. In proportion as the
hydrogen of the vegetable, or that which a-
rifes from the decompoiition of the water, is
forced out in the form of hydrogen gas by the
progrefs of the fire, it is fet on fire immediately
open getting into contaft with the air, water is
Sglio formed, and the greater part of the calo-
O ric

ELEMENTS

ric of the two gaffes becoming free produces
flame. When all the hydrogen gas is dtivea
out, burnt, and agam reduced td water, the re-
maining carbon continues to bum, but without
flame; it is formed into carbonic acid, which
carries off a portion of caloric fufBcient to give
it the gaffeous form ; the reft of the caloric,
from the oxygen of the air, being fet free, pro-
duces the heat and light obferved during the
combuftion of the carbon. The whole vegetable
is thus reduced to water and carbonic acid, and
nothing remains but a froall portion of grey ear-
thy matter caHed afhes, being the only really fix-
ed principles which enter into the cooftitution'
of vegetabtes. /

OF CHEMISTRY. * Hi

The potdh '-btained by this procefs is altvays
left or more faturated with carbonic acid, which
is ealily accounted for : As the'potafli does pot
^fisnn, or at leaft is not fet free, but in propor-
tion as the carbon of the vegetable is converted^
into carbonic acid by the addition of oxygen,
either ftom the air or the water, it follows, thut
each particlt of pctfalh, at the inllant of its for-
niation, or at leafl of its liberation, ts in contact
with a particle of cftrbonic acid, and as there ia
a coniiderable affinity between thefe two fub-
fiances, they naturally combine together. Al-
though the carbonic acid has lefs af^nity with
potaih than any other acid, yet it is diilicult to
feparate the laft portions from it. The moft
. ufual method of accomplifbing this i.s to dilToIve
the potafti in water, to this folution two or
three tiroes its weight of quicklime are added,
then the liquor is filtrated, and evaporated in
clofe veflels ; the faline Jubftance left by the
evaporation is potaih almoft entirely deprived of
carbonic acid. In this Hate it is foluble in an
equal weight of water, and even attracts the
moifture of the air with great avidity ; by this
property it furnifhes us with ati excellent means
of rendering air or gas dry by expoling them to
its adion. In this .ftate, it is foluble in alko-
hol, though not when combined with carbonic
acid ; and Mr Berthollet employs this property
as a method of procuring potalh in the ftate of
perfedl purity,

Oa All

ELEMENTS

All vegetables yield kfa or more of potafli in
confequence of combtfftion, but it is furmftied
in various degrees of purity by different vege-
tables ; ufually, indeed, from whatever fource
it be procured, it is mixed with different falts,
from which, however, it is eafily feparable. We
can hardly entertain a doubt that the afhes, or
earth, ^vhich is left by vegetables in combuftion,
pre-exifted in them before they were burnt,
forming what may be called the Skeleton, or
ofleous part of the vegetable. But it is quite
otherwife with potafh ; this fubltance has never
yet been procured from vegetables but by means
of procelTes or intermedia capable of fumtlhiog
oxygen and azot, fuch as combuftion, or by

OF CHEMISTRY. ,213

lunatioDS which are proper to each, and confe-
quently dtfttngui(h them from each other ; thus
Ibda, which, as obtained from marine plants, is
ufually entirely faturated with carbonic acid,
does not attrad the humidity of the atmofphere
like potaih, but, on the contrary, it deGccates,
its cryftals efflorefce, and are converted into a
white powdei having all the properties of foda,
which it really ts, kaviog only loft its water of
cryAallization.

, Hitherto we are not better acquainted with
the conflituent elements of foda than with thofe
of pota(b, being equally uncertain whether it
previonJly exifted ready formed in the vegetable,
or if it be a combination of elements effeded by
combuftion. Analogy leads us to fgfpei^ that
azot is a conflituent element of all the alkalies,
as is the cafe with ammoniac ; but we have only
flight prefumptions, unconfirmed by any decilive
experiments, relpefling the corapofitioa of pot-
afh and foda *.

03 5 3-0/

* There «M fiuie czpuiinaits rdited is the Tran&c-
dons of the TuriB Academy, which give reifon for fnp-
pofing An foda is t modification of magaefia : This latter
Jabflmce, according to the expcrimeius detailed by Baton
Born, and meationcd in the additional leAian of this chap-
ter, feems to be a metallic oxyd. From analogy, we may
prefume that potafli is likewile a metalliG fubRance, in
bme hitherto unknown Hate of combination. We fhall
thus exclode all the alkalies from the cla& of Cmple elc-
nottty fubAaneesiwT.

^14 ELEMENTS

$ 3. Of Ammcniac.

We have, however, very accurate knowledge
of the compofition of .ammoniac or volatile al-
kali, as it is called by the old chemifts. Mr
BerthoUet, in the memoirs of the Academy for
17S4, p. 316. has proved by analyfis, that loop
parts of this fubftance conlift of about 807 parts
of azot combined with 193 parts of hydrogen.

Ammoniac is chiefly procurable from animal
fubllances by diftillatipn, during which proce^
the azot and hydrogen neceflary to its forma-
tion unite in proper proportions ; it is not, bow-
ever, procured pure by this procefs, being mix-
ed with oil and water, and moftly faturated with
carbonic acid. To feparate thefe fubfiances, it

OF CHEMISTRY. 215

j 4. ' Of Lime, Magnejta^ Barytes, and Argill.

The compoiition of thefe four earths is totally
unknown, and, until hj new difcoveries theli
-conftituent elements are aft:er£ained, we are cer-
tainly auChoiiied tq confider them as llmple bo-
dies. Art has no Ihare in the prpdudion of
thefe earths, as they are all procured ready
formed from -nature ; but, as they have all, e- '
fpecially tbe three firA, great tendency to com-
htnation, they are never found pure. Lime i&
nfually fatucated with carbonic acid in the ftate
of chalk, calcareous fpars, mod of the marbles,
&c.; fometimes with fulphuric acid, as in gypfum
and plafter ftoqes ; at other times with fluoric
add forming vitreous or fluor fp£rs ; and, laftly,
it is found in the waters of the fca, and of faline
fprings, combined with muriatic acid. Of all the
falifiable bafes, it is the moft univerlaUy fpread
.through nature. ^

Magnefia is found in mineral waters, for the

.moft part combined with fulphuric acid ; it is

iikewife abundant in fea- water, united with murl-

O4 Stic

French chemifls. Uxa, tnma, »id ammona, are equally
convenient for ofe as potftSa or potafh, foda, and amnao-
niac, and they are not fo ape to lead into iniftakes; for the
words of the new French chemical nomenclature have too
mnch refemblance to old terms ufed for very dlfleient Tub-
fluces, or at leafi for very di&rent ftates, in a chemical
Jf^t, of the fame lubftancea. — T.

ii6

E L E MEN T S

atic acid ; and it exifts in a great number of
flones of diSerent kinds.

Barytes is much leTs common than tbit two
preceding earths ; it li found in the mineral king-
dom, combined with fulphuric acid, forming
heavy fpars, and fometiined, though rarely^ uni-
ted to carbonic acid-

ArgtU,' or the bafe of alutn, having le& ten-
dency to combination with the other earths, is
often found in the ftate of at^ill, uncombined
with any acid. It is chiefly procurable from
clays, of which, prt^tly fpeaVing» it is the bafti,
■pr chief ingredient*.

" On the 4th of Novembfcr 1793* Dr Hope,
now afTociated in the Edinburgh chemical chair

OF CHEMISTRT. aiy

count of this important difcovery cannot be given;
for which the re^er is referred to the Tranfac-
tions of the Ro^ai Society of Edinburgh btion-
tites has a pungent acrid tafte ; is foluble both in
hot and cold water, but much more fo in hot,
from which it Cryftalizes in cooling ; its cold fo-
Jutions anrad carbonic acid from the atmofphere,
form a cruft of carbonate of Strontites on the fur-
&ce, which breaks and falls to the bottom, ex-
a£t]y as in lime, and is rediflblred by an excels
of acid. Strontites combines with the various
acids, forming neutral falts ; and poffefles diffe-
rent affinities with the acids from the other known
earths. One of its moH remarkable properties,
both when pure and in combination with the
acids, is that of tinging the flame of combuftible
bodies of a deep blood red colour ; to produce
which eSe£k, however, fome moifture muft be
prefent. The order of affinities of the principal
acids with Strontites, as determined by Br Hope's
experinlents, is as follows :

Sulphuric. Nitric. Acetous.

OkoUc. Muriatic. Arfeniac.

Tartarous. Succinic. Boracic.

Fluoric. Phofphoric. Carbooic.

Its order of affinities with the feveral acids.
reluive to the other falifiable bafes, fo far as af-
certained by Dr Hope, are inferted in the refpec-
tive tables in Part II*.'*

§5-0/

* Tbc whole of this aceount of Stnmtitei, was added by
<be tranjlator to the third Edition.— T-

ELEMENTS

$ 5. Of Metallic Bodies.

The metals, except gold, and fometimes fil-
ver, are rarely found in the mineral kingdom in
their metallic ftate, being ufually lefs or more
faturated with oxygen, or combined with ful-
phur, arfenic, fulphoric acid, muriatic acid, car-
bonic acid, or phol'phoric acid. Metallurgy, or
the docimailic art, teaches the means of fepara-
ting them from thefe foreign matters ; and for
this purpofe we refer tofuch chemical books as
treat upon thefe operations.

We are probably only acquainted as yet with
a part of the metallic fubflances exifting in na-
ture, as all thofe which have a ftronger affinity

OF CHEMISTRY. aip

nieUllic or reguline ftate, ate the following fe-
venteen.

hain Namu,

JfMgriJh Namu.

I. Aifenicuin

Arfenic.

2. Molybdenum -

Molybdeoa.

3. Tungftenum

Tungftein.

4. Mangaoefum -

Manganefe.

'5. Nickolum

Nickel

6. CobalCum

Cobalt.

7. Birmutbum

Bifmutlb

8. Antimonium

Antimony.

9. Zincum

Zinc,

10. Fcrruin

Iron.

XI. Stannum

Tin.

11. Pluinbuni

Lead.

13. Cuprum

Copper.

14. Mercurium

Mercury.

15. Argentum

Silver.

16. Aurum

Gold.

17. Platinum

Platina.

I only mean to confider tbefe as fali6able bafet,
without entering at all upon the conlideration of
their properties in the arts, and for the ufes of
fociety. In thefe points of view each metal
would require a' complete treatife, which would
lead me far beyond the hounds I have prefcribed
fat this work.

i6.qf

ELEMENTS

^6. Of tbe Metaiik Nitare of the Eartbt •.

In tbe laborfttoiy of the Academy of the mines
at Chemnitz in Lower Hungiai'y, fome experi-
ments have been lately made, t^ Meflh Tondi
and Ruprecht, hy which the number of the me-
tals feems to be confiderably augmented, fiefides
afcertaining the real metallic nature of Tung-
ftein, Molybdena, and MaogaDefe* which fome
chemifls had doubted* but all of which bare
been reduced to tbe reguline form by thefe two
chemifts, they bmve fucceeded in procuring me-
tallic reguli from Chalk, Magnefia, and Barytes.
Of thefe experiments it may be proper to give
fume account In this place, from the defcription

OF CHEMISTRY. 321

colour and uniform metallic lufire ; its texture
is lamellated, compofed of large diftili£t lamellae,
which crols each other ; it Is brittle, but not
hard, and readily takes a polifh ; is attradted by
the magnet, notwitbftanding every poffible pre-
caution to fcparate any martial oxyd which might
have previoufly been mixed with the mineral^
The fpecific gravity of this new metal is 6.744,
water being taken as unlt^.

Magrujia,

By treating t)if (ubonat of magneEia in the
iamc manner, they obtained a convex lump or
globule of metalUc regulus, of a bright grey co-
lour, fimilar to pUtina which has not been fully
purified &om iron. This regulus is harder than
thoiie obtained from tungftein or molybdena, it
is granular and ibmewhat ftriated in its teicture
when broken, and is not affetfied by tbc magnet.
Its fpecific gravity, and other properties have
not yet been afcertaioed.

Cbalk.

By the fame method of proceeding, a reguluf
has likewife been procured from carbonat of
chalk. The button was convex and very com-
pad in its texture ; in colour and lufture it came
very near to the appearance of platina, and it
took a fine polifh. Its fpecific gravity, and che-
mical

ELEMENTS

mical relations, have not jet been afcertained hf
experiment.

Thefe experiments have been frequently re-
peated by the above-mentioned gentlemen, and
always with the fame refults. Should they e-
ventually be confirmed by rigorous examina-
tion, a new light will be thrown on feveral of
the moll difficult parts of chemiftryby thefe dif*-,
coveries, which hare already been in a great
meafure predifted, by the conjedure of Mr La-
Toifier^ who fuppofes that tbofe fubftances, which
have long been confidered as primitive earths,
are only metallic oxyds combined with oxygen^
and that their redudion has hitherto been pre-
vented by the attradion which fubfifts between

OF CHEMISTRY. 223

' and improvement from their influence. Pcr-
' haps gold and filver are the only pure metal-
' lie fubftances hitherto known, as it is proba-
' ble, that fome part of the, till now unknown,
' metals, from the earths employed for facilita-
' ting the fmelting of ores, may mix with the
' metals which we eztrad from thefe ores, and
' debafe them ; fo that, inftead of fimple or

* pure metals, which they were formerly con-
' lidered, thefe may only be alloys, of the in-
' gredients of which we are ftill ignorant. Per-
' haps the regulus of b^rytes and of chalk are
' foluble in the £ime acids, and precipitated by

■ the fame eledive attradions, as the regulus
' of copper, which may be the caufe of this

* mixture not beiflg hitherto fufpeded. From
' this mixture, 01 alloyage, the harflinefs and
' greater or lefler duftility of iron, copper, tin,
' and other metals, may be derived. AH thefe
' conje^ures can only be afcertained or reje£t-
' ed, when all thefe newly difcovered metals

■ fhall have been properly examined, and their
' chemical affinities compared accurately with
' thofe of the metals already known, and with

* each other. One thing feems highly proba-
' ble, that one or other of thefe new metals
' will precipitate fome of the other metals froip
' folutions in a metallic form, and. by this pro-
' perty many metallurgic proceflcs may become
f greatly facilitated and abridged."

Thefe

ELEMENTS

Thcfe difcoveries give reafon to hope that
chemiftry may one day arrive at a moft beauti-
ful ftate of limplicity. It is perhaps no im-
probable conjedure, that all the bodies in na-
ture may be referred to one clafs of fimple com-
buftible elementary fubftances^ to oxygen, and
to caloric ; and that, from the Tarious combi-
nations of thefe with each other, all the variety
produced by nature and art may arife. The on-
ly known difference between metals and pure
combuftibles, as they are called, is in degrees of
qualities : I'bey are aU combuftible, that is, they
all combine with oxygen, though under differ-
ent degrees of temperature : They are all £blid,
or liquid, or aerifom, fi;ced or volatile at differ-

O^ CHEMISTkr. 225

excluded from a clafs with- which th^y agree
in fo many particulars, becaufe their points of
fufion and volatility are perhaps as many degrees
below thofe belonging to mercury as this latter
falls ftiort of thofe of iron ; or why Ihould car-
bon, fulphur, and phofphorus, not be contidered
as metals, becaufe their fpecific gravity, and luf-
tre, and duftility, differ from the bodies called
metals, which differ fo much in thefe particulars
among themfelves ?

To thefe three new metals Mr Tondt wirties
to give the names of borbonium, for the regulus
ofbarytes; aujlrum, for tbe regulus from mag-
nefia ; and partbenam for that of chalk. It
were hard to deny a djfcoverer the right of gi-
ving names to his own difcoveries, withoitt fome
reafonable obje<%ion ; but thefe names would
introduce confufion into chemical nomencla'
ture, which it has been the great objedl of the
French chemifts to reform, and render regular;
wherefore I would propofe that they Ihould be
named barytum, magnejium, and cakum : . Thefe
accord with the reformed old names of the fub-
ftances from which they are procured, merely
by changing to the neuter gender, in which all
the names of the metals -are placed in the new
nomenclature, and then the three, formerly cal-
led earths, will be oxyds of thefe metals refpec-
tiyely, or baryta, magnejta, ani caka, iffingle
terms are preferred, thefe latter being in the femi-
P nine

326

ELEMENTS

nine gender, which is appropriated to alkaline
fuhftances in the new nomenclature.

It mull not, however, be concealed, that the

[ truth of thefe difcoveries is ftrongly contefted by

r-verycminentchemids ; who infill that the metal-

tlic buttons, produced in the experiments of Meflrs

iTondi and Ruprecht, arife entirely from the

(nanganefe and iron of the charcoal, or from fome

fimilar alloyage of materials from the crucibles or

lefts employed, and that they have no farther

pretentions to be confidered as diftinft metals

1 the fidcrite, now known to be phofphoratcd

iron, or than plumbago, or black-lead.

Mr Klaproth, a celebrated chemifl at Berlin,
has lately difcovered a new metal, to which be
[I'gives the name of Uranium ; and he diftinguifhes
tits various mineral forms by the generic term of
[ Uranite. His numerous experiments on this fub-
Ijcift are publilhed in Crell's Chemical Journal,
1 and in the Annales de Chymie j and the follow-
Jng general account of the minerals, and of the
itaetal, was confidered as proper to be given in
ihis place.

The Uranite occurs in feveral forms, which
were formerly overlooked, by chemifts and mi-
neralogifls, being confidered as very poor ores
of copper, becaufe they moftly contain a little
of that rat;tal : They are chiefly found near
Johan-geor jon Stadt in Saxony, Salfeldt in
Thuringia, and Joachims thai in fioher

OF CtlEMlfeTRY. 4*7

Tbefe may be divided' inte three geherB, tiie
OchreoUt^ the fpathifonti, arid the ciineraBztd,
or Orel 'The ochi^ous, or iifanitc ochre, called
uranit-oker, Jli the Germftn language, is of a le-
mon yellow ctAouc of Various fhades^ and being
frequently tttoi* 6r ItfA intxed ifith.iron ochre,
its colour is thertby changed to vatioas fhades
of brown; fbrtietimes It is in a powdery ftate,
arid at otber timet it is caked togethet- in rtiaflbs
of different degrfies 6f cortitjaanefB ; it is gene-
rally found corering or adhering to pieces of
the ihineralixed uranite. The fpathiform, or
aranite fpar, Called in German uranii-Jpalb, the
cbalkolUb of Mr Wehici', is generally of a deep
gtafs green colour, fometitnes verging to a filver
white, and dt Other times to a light yellowilh
green j it isfotnetlmes cotllpaft and irregular in
its form, and is fometimes ctyftalliied in ftnall
fliining Iquate and traafparcnt tables, which are
occaiiohally fo thick as to be aJmoft cubes ;
thefe cryflals dre lamellated in the fra£lure, and
feel foft to the touch ; tiity are often found in
fpots, fcittcted over the futface of micaceous
fhift, granite, or a liiixtute of quart! and black
uranite ore. Both the ochre and fpar dilTolre en-
tirely in nitric acid. The mineralized, or uranite
ore, called in German uranit-erz, pecb-blende, or
pecb-erz, is of a dark hlack-hrown colour ; it is to-
lerably hard, has a greafy luflre, breaks compact,
and is black where fcratched ; it is very heavy,
P2 the

2i8 ELEMENTS

the fpccific gravity being 7.500 ; it does not raclc
in the fire by itfelf, but is reduced under llie
blow-pipe with the addition of phofphoric acid,
to a green vitreous globule ; it diflblves imper-
fciftly in the acid;, but beli in the nitrous, ttie
dilToIuCion being of a pale white-wine colour.

Uranium, the metal procured from thefe mi-
neral fubflances, is even more difGcultly futed
than manganefe ; its fpecilic gravity is 6.440; it
is of a dark grey colour, becoming brown when
fcratched; its brilliancy is flight; and it is rather
foft, being eafily cut with a knife or file. It dif-
folves very imperfedly in the fulphuric and mu-
riatic acids, but very readily, and with confide-
rable evolution of heat, in nitric and mtro-niu-
xiatic acids : From this diflblution its oxyd is
precipitated of a yellow colour by the pure alka-
lies, and the precipitates arc re-diffolved by an
excefs of alkali; with the alkaline carboiiats the
precipitates are whitifli, and reddifti brown when
the prulfiats are employed : Thefe oxyds do not
melt under the blow-pipe, without addition, but
with foda and borax they melt Into a brown
button, and with phofphoric acid the button is
of a green colour.

OF CHEMISTRY. 129

« • • I .

^C HAP. XVII. ;• ' ^

Continuation of the Obfervatipns upon SdJifiable
BqfeSf and the Tahhaiion of Neutral Salts.

I •

I

T Ts necdOTary to remark, that earths and al-
kalies unite with acids to form ' lieutral
falts without the intervention of ^ny medium,

whereas metallic fubftahces are incapable of

• <■».»-■■■ '*■« ... ..^i» ..

forming this combination, without' being pre-
vioufly lefs or more oxygenated ; ftridly' ipealt-
ing, therefore, me;tals are "not iblubleiri acids,
but only, metallic oiyds^ ' Hence, whe^a me-
tal is put into an acili. for folution, it is heceflary,
inthe^rft place, th^t ft become pxygie'nated,
either by lattfa(?iing o:!i.ygtn from the acid; or
from the water, with which the' acid is "diliifeq;
or, in other word^; that a'lhelal cannot be' oif-
iolvcd iii an acid, '.unleis!' the o;cyfren,'e^thiftif df
the acid, or of the water mixe4 Viln it; haS a
urqng^r afSnity to!th^ metal than'to the hyaro-
gen or theacidma^leB-^e'; WwBUt'UlfldrfhWto

the vi^ater, b't of Itie kcid in^WhulHVi^Mif^. ^lie
explan^ttion of the principal phenomena of mc-

P 3 tallic

33°

ELEMENTS

tallic diiTolution depends entirely on this limple
obfervation, which was overlooked even by the
iHiiftrious Bergman.

Tlie firftandmpft ftriki/igof thefe phenome-
na is the effervefccnce, or, to fpeak lefs equivo-
cally, ;he d(fengagement of gas, which takes
place 4^^>ng ti)e fplution j in the folution^ made
in nitric acid, this eifervefcencc is produced by
the difengagement of nitrous gas ; in foluttons
with fulpburjc acid it is either fulpburous acid
gas or hydrogen gas, according as the osydation
of the metal happens ^o'be made at the ex-
pence of the ("ulphuric acid or of the water.
As both nitric acid ajid water are compoled of
clcm^T}ts,_ wt(ich, when fcparate, can only esift
i» the "gafleoiis form, at lead' in the common

:?v-:i

OF CHEMISTRY. 131

perature, it is difeng^ed, and occafions effer-
vefcence.

The fecond obfervable phenomenon is, that,
when the metals hav^c been previoufly oxydated,
they all diflblve in acids without effervefcence :
This is eafily explained ; becaufe^ not having now
any occafion far combining with oxygen, they
neither decompofe.Jhe acid nor th^ water, by
which deeompofition, in the former cafe, the
efiervefcence is opcajpioned.

A third phenomonpn, which requires parti-
cular confider^tipni is, that none of the metals
produce eflfervefceoce by folutioq. in oxygenat-
ed muriatic acid. During this procefs the ipe-
tal, in the firft placCj, carries off the excefs of
oxygen from the oxygenated muriatic acid, by
which it becomes cxydated, and reduces the
acid to the ftate of ^ ordinary muriatic acid. In
thiS'Cafe there is no produdion of gas ; not that
the muriatic acid does not tend to exift in the
gaiT^ous date iu tbe comipon temperature, which
it does equally with the acids formerly mention*
ed, but becaufe this acid, which otherwife would
expand into gas, finds more water combined with
the oxygenated muriatic acid than is necelTary
to retain it in the liquid form ; hence it does not
difengage like the fulphurous acid, but remains,
and quietly diflblves and combines with the me-
tallic oxy d previoufly formed from its fuperabun-
dant oxygen.

P4 The

532

ELEMENTS

The fourth phenomenon worthy of notice is,
that metals are abfohitely infoluble in fuch acids
as have their bafes joined to oxygen by a ftrong-
er affinity than thefe metals are capable of ex-
erting upon that acidifying principle. Hence
Jjlver, mercury, and lead, in their metallic ftatw,
are infoluble in muriatic acid, but, when previ-
oufly oxydatcd, they become readily foluble
without eftervefcencc.

From thefe phenomena it appears that oxy-'
gen is the bond of ttnibri iMtween metals and
ucids ; and from thistle are lead to fuppofe that
oxygen is contained in'aUfubffianccs'which have
a ftrong affinity with acids: Hen&e it is very pro-
bable that the four eminently feliflable earths
contain oxygen, and that their capability of u-

OF CHEMISTRY.

^33

menclature, are placed ; the third contains the
bafes or radicals of thefe acids.

Table of all the known Acids.

I

2

3
4

5
6

7
8

9

10

II

12

13

14

15

i6

IT

i8

>9

Latin Names. t^ngli/b Names.

Acidum fttlpburofom 3iupburous acid
Ikilphuricum Sulphuric
phofphorofum Phofpborous
phofphoricuzu Pholfphoric
oiuriaticum Muriatic
-^ oxjgenatum ^Oxygenated muriatic
nitrpfum Nitroi^

nhricum Nitric

»t'u*\

— osjgenatum iQxjgenated uithc
carbonicum Carbonic
acetofum Acetous

aCcticum Acetic

oXalicum Oxalic

-^tartarofum " Tartjafous
pyro-tartarofnm Pjro-tartarous
citricum Citric

malicum Malic

pjTo-lignofum Pjro-lignous
pjro-mucofum Pyro-mucous

[Bifes.
Sulphur

Phofpboms

Unl^aown f

> Azot.
Csirbon

t

r Coaipoundy
r Sec Obf. ift-

J

* •

fi ■

20. Acidum

* This terjsi might be changed fioi: A^idum n)uribxi-
cum, Murioxic acid.-r-T.

« « • • i •

f In a former note Hydrogen is mentioned as the fup^
pofedbafcotthis^acid.— T. [V

t This might inore conveniently be named Acidum
futroxicum, or Nitroxic acid*— T.

ELEMENTS

LcdtM Names.

Englijb Names.

Bfl/«.

SO. Acidnm galiicnm

Gallic -\

11

pruliicum

Pruffic

21

■ benzoicutn

Benzoic

33

54

—^ fuccinicum
camphoricum

iiaocinic
Camphoric

' Sec ObC Id.

=5

_^— lafticum

Lsftic

36

faccho-laflicuin Saccho-laaic ,

27

— — bombicum

Bombic 1

■ See Obf. 3d.

38
*9

formicum

1^— febacicum

Formic
Sebacic

30
3>

beracicum

1 1 ' fl^oricum

Bontcic

.Flubric

ankwmi

32

aittimoDicuni

AntiBUHUic

Antimony

33-

34

— .— atgemicum
— arieniBCUDi

Aiieatic
Arfeniic* .

Silvy
Arfeuic

33

««- l^rmathicmo

Bifovduc

Bifmiuli

36

cbbalticum

Cobaltic

^<*.lt

37

r ctpricum

Cupric

Copper ■

38

%nnicuip

Staonic

Tia

39

ferriciim

, Ferric

Iron

40

Mwffiiie

fl*

nlerCuneuitl \

Mercunc

M.vcary

OF CHEMISTRY.

• .

235

Latin Noma. Englifi Names. Bqjes^

45. Acidum platinicum ^'Pladnic Ratina

46, plnmbicuai • Plumbic Lead

47, tnngfiicam Tannic Tungdeio

48. ' ■ tinicicam Ziocic Zinc

Ob/ervations an ib^ foregoing Table.

tjiy Tbe baCes or radicals of the acidft from
N^ xl. toN^ 19. iiicliifive/ieein to be formed by
a combimition of carbon and hydrogen ; and the
only difiereoGd appears to proceed from the dif-
fimilar proportions in which thefe elements com-
bine to form the bafca of thefe acids, together
with the diS6i?ent quantities of oxygen in their
acidiflcatiorl. ' A connedled feries of accurate ex-
periments is ftill waited to illuftrate this fubjed
in a ftttisfiiAory maniner.

id J The bafe^ or radicals of the acids from
N® 20. to 26. inclufive, are hitherto very imper-
fedly known y we only "know that hydrogen and
x'arbon are* their principal elements, and that the
pra flic acid' contain^ like^ff^ fbme a'zot;

3^, Th^4Wifes of t!hc -acids 27, ^8, 29, and all
others obtWned Trorft'aniihal fubftances, are ftill
vcty imperfeAly known, and require farther in-
vef^igation ; for they feem to confift of carbon,
hydrogep, pho^horus, and azot, united toge-
ther, but.]the particular proportions of thefe ele-
ments in e^h>. and the degrees of oiydation^ are
upafcertaiaed.

•>

Ih

236

E L E M ENl' S"

In this lid, which co^itaips 48;acids, I have
enumsrated 17 metallic acids . hitherto very im-
perfeflly known *, but upon which' Mr 'Berthol-
let is about to publifli a very important worlt.
It cannot be pretended that all the acids which
cxift in nature, or rather'all 'the 'acidiiiable ba-
fes, are yet difcovered ; but on the other hand,

-there are confidcrable groundi. :foCi luppofing
chat a -inore accuratie.inTQ£tigation t&an has hi-
therto been atteidpted,. will 'diminiilk the num-
ber df the vegetable acids, by OiQwing. that fe-

-veralpf thefe, at prefeoi) copfidcf^ as diflind
acids, are only modificatiojis ofiQtherai All that
catt be done ii) -tht) prefenc.4at«ofiour .know-
lodge is, to give;a view of chemiftiy, as it really
j$, aiid to eAablifh . fundamental principles, by

OF CHEMISTRY. ?j7

tb 1152^. This number is upqn.tJbe fuppofi-
tion that the . metallk acids are capable of dif^
fpLving other in^tal9» which is a new branch of
chemiftry, not hitbUtoinveiligated^upoa which
depends . all the metallic combinations named
vitreous., Thete i& rcafon to;believe. that rn^iy
of thefe fuppofable faline combinations are not
capable of being £>rmed, which muft greatly
reduce the real numbei^ of neutral falts produ*
cible by nature and art. Even if we :fuppofe
the real number to amount only to fiive or iisL
hundred fpecies of pofiible neutral falts, it is e-
vident that, were we to diftinguifli them, after
the manner of the older chemilb, either by the
names of their firl^ difcoverers^ or by tejms de«
rived from the fubftances from, which they .Are
procured, we (hould; at lad have fuch ^ confer
lion of arbitrary defignations, as.no memory
could poffibly retain. This method might be to-
lerable in the early ages of chjeroiftry^ or eyen
till within thefe twenty years, when; only about
thirty fpecies of falts were known ; but, in the
prefent times, when the number is augAienting
daily, when every new acid gives us 24 or 48.
new falts, according as it is capable of one or

two

♦ This number excludes all triple falts, or fuch as con-
tain more than one (alifiable bafe, all the fairs whofe bafcs
are over or under iiiturated with acid^ and thofe formed
by the nitro-muriatic acid.— T.

ELEMENTS

two degrees of oxvgenatioa, a new method ta
certuulj aecefiiirr. The molkod bete adopted,
iriwn trutn the nomenclamte of the acids, is
pertedl* aiuiogtcal, and, following NsCine in
rhe timpUcir'' oc her apcntiona. gives a isitaral
isti e^y scsceoclacare, spplicahle to ereir poT-

It. r.'--=z =u3tes r3 the di&tctt acids, wc
-i^j 4iTrai&si ta* c-amiiua otauei.T» b* tfe ge-
-vr.srAl r:m: A-a£. mai lam didinguflied each
- -c.os >v t:i« smie ^~ xs ftcjUar addifiahic
ALi;. H-scv Che «:»& axned brv tte oxT^eiB-
rvc. -"i" ixjriir. jaaabaca^ cvbca. &c. uc

OF CHEMISTRt. 239

foidffulpbat of artifnofiiacyfulpbat of lime^ fulpholt
ofiron^ &c. As we are acquainted with 24 (ali-
fiable bafes, alkaline, earthy, and metallic, we
have confequehtly 24 fulphats, as many phof-
phats, and fo on through all the acids.

Sulphur is, however, fufceptible of two de-
grees of oxygenation, the fir ft of which produ-
ces fulphurous, and the fecond, fulphuric acid ;
and, as the neutral falts produced by thefe two
acids have different properties, and are in fa(Sk
different falts, it becomes necelTary to diftin-
guilh thofe by peculiar terminations ; we have
therefor^ diftinguiftied the heuttal falts foriiidd
by th6 acids in the firft or leflef degree of oxy-
gensitioil, by changing the termiaatlbn al iqto
j>, /as fulpbites, pbofpbites *, &c. "thus, oxy-
genated

* As all the fpecific names of the acids ia the new iio-
xnenclature are adjedives, tbey would have applied &v,e-
rally to the various lalifiable bafes, witliout the inveotioii
of other terms, with perfed difiinfioeis. ^tlius, fnlhim^
TQUipQiafby ixAfulphttrk potafb^ are equally <^i{(iha, as
fulphitt ofpotafb^ zadjitlpiat ofpotdjb ; and have thi^ ad-
vantage of being more eafily retained in the memotyy be-
caufe more naturally arifing from the names of ackb
themfelves, than the arbitrary terminations adopted ^by
Mr Lavoifier. Thefe propofed terms are like wife v^tj
readily and diHindly expreHible in I^atin, thus, Potafja^
or rather, as I have formerly obferved, X/x/i, Sulphuroja^
and Sulpburicaj and are equally diflinflive with, and more
readily remembered than, the Latin terms of the new n^^
mcncbturc, Snlphis and Sulphas Potajfcv. — T.

^40

ELEMENTS

degrees ^^

gcQated or acidified fulphur, in its two degrees
of oxygenation, is capable of forming 48 neu-
tral falts, 24 of which are lulphitcs. and as ma-
ny fulphats : This is likewife the cafe with all
the acids capable of two degrees of osygena-
tion *.

It were both tirefome and unneceflary to fol-
low thefe denominations through all the varie-
ties of their poiliblc applications ; it is enough
to have gi\'en the method of naming the various
falts, which, when once well underllood, is ea-
fily applicable to every poflible combination.
The name of the corabuftible and acidifiable
body being once known, the names of the a-. 1
cid it is capable of fonning, and of all the neu- 1
tral combinations the acid is fufceptible of en-
tering

■ There is yet a ihird degree of oxygenation of feveral
acids, as ihc oxygenated muriatic and osjgenated nitric a-
cida. The terms applicable to the neutral falts refuliing
from tbe union of ihefe acids with fatiliable bafcs is fup-
plied by the Author in the Second Part of this Work.
Thefe are formed by pre6xing the word oxygtnated ta
the natne of the fait produced by the fecond degree of ■
oxygenation. Thus, oxygcnattd mwu^t oi ^at^^, oxyge-
nated nitriat of foda, 6tc. Or if the change 1 have pro-
pofcd in a former note on the nomenclature of tliefe two
acids be adopted, we fhill have utt/rioxic and nitroxt'c pot-
aQl or lixa, in Latin Lixa murioxica, Trona nilroxica, in-
Head of the much longer, and not more dLftinflive expref-
fions, Murias pctajfr oxjrgeaata, N'tras/oda oxygtaata.-^"

r.

i

OF CHEMISTRY. 241

tering into, are moft readily remembered. Such
as require a more complete illuftration of the
methods in which the new nomenclature is ap-
pliedy willy in the Second Part of this book, find
Tables which contain a full enumeration of all
the neutral falts, and, in general, of all the pof-
iible chemical combinations, fo far as is con-
fident with the prefent ftate of our knowledge.
To thefe I fhall fubjoin fiiort explanations, con<-
taining the beft and mofi: fimple means of pro«
curing the diflferent fpecies of acids, and fome
account of the general properties of the neutral
falts they produce.

I fliall not deny, that, to render this work
more complete, it would have been neceflary to
add particular obfervations upon each fpecies of
fait ; its folubility in water and alkohol ; the
proportions of acid and of falifiable bafe' in its
compofition ; the quantity of its water of crif-
talization ; the different degrees of faturatiom
it is fufceptible of; and finally, the degree of
force or affinity with which the acid adheres to
the bafe. This immenfe work has been already
begun by Meff. Bergman, Morveau, Kirwan,
and other celebrated chemifts, but is hitherto on-
ly in a moderate ftate of advancement ; even the
principles upon which it is founded are not per-
haps fufficiently accurate.

Thefe numerous details would have fwelled
this elementary treatife to much too great a

(^ fue ;

^, ELSACENTK

fiz.c ; bcfides that, to have gatiicnd the waeet,
ury materials, and ta bave completed all tta«
icries of esperimentd cequiiite, muft have xfr>
taided the publication of this book fiw auhj
years. Tbis is a vail field for emplajtog the
zeal aod abilities of jouaR chemiits, whom I
would advife to eadeaTour raihec to do well
than to do much, aod to a&ertain, is the firft
place, the compofitton of the acids^ befocc eor
teriag upon that of the neutral lalts. Eveiy e-
dificc which is intended to refift the larages of
time fhould be built upon a fure foundation ;
and, in the prefent ftate of chenuftry, to atteiopt
difcoveries by experinients, either not perfedly
exa£l, or not fufficieatly rigorous, will {errc
only to interrupt its progrefs, inftead of contri-

OF CHEMISTRY.

^4^

PART IL

Of the Combinatioa of Acids with Sali<»
fiabic Vvcdes, and of the Formation of
Neutral Salts.

INTRODUCTION-

IF I fewi ftvi&fy followed the plan at firft
laid down for the condiuft of this work, I
would have confined myfelf, in the Tables and
acc(Hnpanjing obfervations which compofe this
Second Part, to ihort definitions of the feveral
known acids, and abridged accounts of the pro*
cefles by which they are obtainable, with a mere
nomenclature or enumeration of the neutral
falts which refult from the combination of thefe
acids with the various falifiable bafes. But I
afterwards found, that the addition of fimilar
Tables of all the fimple fubftances which enter

(^2 into

544

ELEMENTS

into the compofitioD of the acids and oxyds, to-
gether with the various poflible combinations of
thefe elecnents, would add greatly to the utility
of this work, without beiiig any great increafe to
its fize. Thefe additions, which ace all contain-
ed in the twelve firft feclions of this Part, and
the Tables annexed to thefe, form a kind of re-
capitulation of the firft fifteen Ch^tecs of the
rirft Part ; the reft of the Tables and Sedions
contain all the faline combinations.

It rauft be very apparent that, in this Part of
the Work, I have borrowed largely from what
has been already publifhed by Mr de Morveau
in the Fi rft Volume of the Eneyclopedie par ordre
ties Malieres. I could hardly have difcovered
a better fource of information, efpecially when

OF GHfiMISTRt.

MS

TABLE OF SIMPLE SUBSTANCES.

Simple fubftances belonging to all the kiogdoms of Naturej
ivhlch may be coniidered at the chemical elements of bodies*

£ttgli/b.
Light

New Names.

Latin,

Corre/pondettt old Names.

Caloric^

Caloriciim

Oxygen

Azot
Hydro^n

Oxygenoiti

Azotuin

Light.

{Heat,
Principle or element of heat,
Fife, Igneous fluid.
Matter of fire and of heat.
~ Oephlogifticated air,
Empyreal air.
Vital air, or
Bafe of vital air.
r'Phlogiflicated air or gas^
i Mephitis, or its baie.

Tj . c Inflammable air or gas, or

Hydrogenum J the bafe of inflammable air.

Oxydable and Acidifiable fimple Subftances not Metallic.

Corre/pondent old Names*

The fame names.

The fimple element of char*
coal.

Still unknown^

New Names,

Sulphur Sulphunim

Fhofphorus Fhofphorum

Carbon Carbonum

Muriatic radical Murium

Fluoric radical Fluorum

Boracic radical Boracu;

' ntaicai iJoracum^,^^^^

Oxydable and Acidifiable (imple Metallic SodiM.

Antimony

Arfenic

Bifmuth

Cobalt

Copper

Gold

Iron

Lead

Manganefe

Mercury

Molybdena

Nickel

Flatsna

Silver

Tin

Tungftcin

Zinc

New Names.

Antimonium
Arfenicum
Bifmuthum
Cobaltum
^ Cuprum
Aurum
Fcrrum
Plumbuni
Manganum
Mercurium
Molybdenum
Nickolum
Platinum
Argentum
Stannum
Tungflenum
Zincum

CL3

I"

3.

Corre/pondtHt old Namts.
" Antimony.

Arfenic.

Bifmuth.

Cobalt.

Copper.

Gold.

Iron.

Lead.

Manganefe.

Mercury.

Molybdena.

Nickel.

Platina.

Silver.

I Tungfleint
[Zinc.

SaltfiabU

24^

ELEMENTS

Lime

Sal'i&able Co

Ulin.

Galea

Magoe&a MagneCs

Barjtes Baryta

ArgiU Argilla

Silex Silica

Stroniites Strontyta

iple Etiicbj Subtlancei.

CarTtJfoiiiUBl otJ Ttanti.

C Chalk, calc&rcous earth,
> Quicklime.

C Magnefia, bafe of Epfom Ult,
^ Calcined or caultic magaefia.

Baryics, or beavy earth.

Clay, earth of alum.

Siliceous or vitrifiable earth.

Newly dUcovered.

Sect. I. Obfervations upon the Table of Simple
Sub/lancet.
The principal object of chemical experiments
is to decompofe natural bodies, lb as feparately
to examine the different fubftances which enter
into their corapofition. By confuItinK chemi-

Kit CHiEMtfef RY. ^47

%dr^ce4, thert (h^ fadicfih offfii ^ctds tft not
Ml fflSi^ ^ftteSifeirtii ThaiSy 6F the* beiftg, like
the Dilf JMriheiple, fedtttpoM vlf hJHdfogen and
cAi*dn. Ev^ tWt bafes of tieiittal Talts feite
been proved by Mr Berthollet to be compbMis^
as he has (hewh that ammoniac is compofed of
azot and hydrogen.

Thus, as chemiftry advances towards pcrfec-
tion, by dividing and fubdividing, it is impofli-
ble 16 fay where it is to end ; and thefe things
we at prefent fuppofe fimple may foon be found
quite otherwife. All we dare venture to affirm
of any fubftance is, that it muft be confidered
as fimple in the prefent date of our knowledge,
and fo far as chemical analyfis has hitherto been
able to (bow. We may even prefume that the
%iaaths m^A iooh c^afe to be confidiered as fiitiple
bodies ; thfey are the! ohljr bodies of the falifia-

bife clais Which havfe iio ttnd^hcy tb unite with

oxygen i and I am miich inclined to believe
that this proceeds from their being already fa-
turated with that element. If fo, they will
fall to be confidered as compounds confiding of
fimple fubftances, perhaps metallic, oxydated to
a certain; degree. This is only hazarded as a
probable conjefture ; and I trull the reader will
take care not to confound what 1 have related as
truths, fixed on the firm bafis of obfervation
and experiment, with mere hypothetical fpecu-
lations.

0^4 The

a<t ELEMENTS

T'w: fmbd aliiaiiy., pota&u and iods, aze »-

evi^c!!' v '.utnyjuud fubflitnceL*, thmigiiweMir
jgii-j.-H->it h\ vtA uiutt we the titaoaaxt tiiej xb:

Taxix

OF CHEMISTRY.

.Table qf compound txydable and acidlfidbk bafes. ■

Ozjdablc or acidiSable
Wes, from the mine-
ral kiogdom.

Ozydable or acidifiable
bydro-carbonoiu or
carboDO-fa jdrous radi-'
call, from the vege-
table kingdom.

OxTdablc or acidifiable
radicals from the ani-
mal kingdom, which
moQIy contain azot,
and freqacotlj phof-
phonu.

NaiRis of the Radicaii.

Nitro muriatic radical*,
or bafe of the acid for-
merly called aqua regis.

TartaroDS radical or bale.

M^lic

Citric

Pyro-lignoia

Pyro- mucous

PyrO'tartarous

Oxalic

Acetous

Succinic

Benzoic f

Camphoric

Gallic

La£Hc

Saccbob&ic

IBombtc
Sebacic
Lithic
(.Pruffie

Sect.

Nitfe.— The radicals from the vegetable kingdom a(k
converted by a firfl degree of oxygenation into vegetable
oxyds, fuch as fugar, llarcb, and gum or mucos : Thofe
of the animal kingdom by the &me means form animal
o^ds, as lym^, S^c.— A.

* This, for the prcCuit) may be named Azo-muriai
nntil the radical of muriatic acid be difcovered ; or, at
leall, till the difcovery of hydrogen being that radical be
uo^ueAionably a(certained.'~-T.

ELEMENTS.

Sect. II. — Ohfirvatiotis upon the Tabte of Com-
pound Radicals.

The older chemifts being unacquainted with
the compofition of acids, and not fufpefting them
to be formed by a peculiar radical or bafe for
each, united to an acidifyingprinciple or element
common to all, could not confcquently give any
name to fubftances of which they had not the
moft diftant idea. We had therefore to invent
a new nomenclature for this fubjeift, though we
were at the fame time fenfible that this nomen-
clature mufl be fufceptiblc of great moditicatiaa,
when the nature of the compound radicals filall I
become better underftood ". '

The compound oxydable and acidifiable ra-
dicals from the vegetable and animal kingdoms,
enumerated in the foregoing table, are not hi-
therto reducible to fyftematic nomenclature, be-
caufe their exaA analylis is as yet unknown.
We only know in general, by fome experiments
of my own, and fome made by Mr Haflenfrati,
that mod of the vegetable acids, fuch as the
tartarous, oxalic, citric, malic, acetous, pyro-
tartarous, and pyro-mucous, have radicals conr-
pot'ed of hydrogen and carbon, combined in
fuch

' See Part I. Chap. XI. upon tiiis fubjefl.— A.

OF CHEMISTRY. 251

fuch a waj as to form fingle bafes, and that
thefe acids only diflfer from each other bynhe
proportions in which thefe two fubftances «nter
into the compofition of their bafes, and bj the
degrees of oxygenation which thefe bafes have
received. We know &rther, chiefly, from the
experiments of Mr BerthoUet, that the radicals
from the animal kingdom, and even fome of
thofe from v^etables, are of a more compound
nature, and befides hydrogen and carbon^ that
they often contain azot, and ibmetimes phof-
pborus ; but we are not hitherto poflefTed of
fufliciently accurate experiments for calculating
the proportions of thefe feveral fubftances, Wc
are therefore forced, in the manner of^ the older
chcmifts, ftill to name thefe acids after the fub-
ftances from which they are procured. There
can be little doubt, that thefe names will be laid
aiide when our knowledge of thefe fubftances
becomes more accurate and extenlive ; the
terms, bydro-carbonous^ bydro^arboniCj carbom*
hydrous^ and carbono-bydric *, will then become
fnbftituted for thofe we now employ, which will
<hen only remain as teftimonies of the imperfeft
ftate in which this part of chemiftry was tranf-
mitted to us by our predcceflbrs.

It

♦ See Part I. Chap. XL upon the applicatJon of thefe
names according to the proportions of the two xngredU
cots.— A.

25^

ELEMENTS

It H evident, that the oils, being compofed of
hydrogen and carbon combined, ate tme cax-
bunu-hydrous or hydro-carbonous radicals ; aod,
indeed, by adding oxygen, they are conTcitible
into vegetable acids and oxyds, according to
their degrees of oxygenation. We cannot, how-
ever, affirm that oils enter in their entice ftate
into the compofition of vegetable oxyds, and «-
cids ; it !•> poffible, that they prerioufly lofe a
part either of their hydrogen and carbon, and
that the remaining ingredients no longer exift in
the proportions ncceflary to conftitute oils. We
Jlill require farther experiments to elucidate thefe
points.

Properly fpeaking, we are only acquainted with
nd radical from the mineral king

OF CHllMISTRY. 453

conceptions of the nature of thefe combinations
arc not hitherto fufficiently accurate. We
know in general, that all bodies in nature are
imbued, furrounded, and penetrated in every
way with caloric, which fills up every interyal
left between their particles ; that, in certain
cafes, caloric becomes fixed in bodies, fo as to
conftitute a part even of their folid fubftance,
though it more frequently adts upon them with
a repulfive force, from which, or from its ac-
cumulation in bodies to a greater or lefTer de-
gree, the transformation of folids into 9uids,
and of fluids to aeriform elaflicity, is entirely
owing. We have employed the generic name
gas to indicate this aeriform (late of bodies pro-
duced by a fufficient accumulation of caloric ;
fo, that, when we wifh to exprefs the aeriform
ftate of muriatic acid, carbonic acid, hydrogen,
water, alkohol, &c. we do it by adding the word
gas to their names ; thus muriatic acid gas, car-
bonic acid gas, hydrogen gas, aqueous gas, alko-
holic gas, &c.

The combinations of light, and its mode of
afting upon different bodies, are ftill lefs known
than thofe of caloric. By the experiments of
Mr BerthoUet, it appears to have great aiBnity
with oxygen, is fufceptible of combining with it,
and '^contributes along with caloric to change
it into the ftate of gas. Experiments upon ve-
getation give reafon to believe ^that light com-

bines

254

ELEMENTS

tones with certain parts of vegetables, and that
the green of their leaves, and the various co-
lours of their fiowers, are chiefly owing to this
combination. This much is certain, that plants
which grow in darknefs arc perfedly white,
languid and unhealthy, and that to make them
recover vigour, and to acquire their natural co-
lours, the direct influence of light is abfolutely
neceffary. Somewhat limilar takes place even
upon animals : Mankind degenerate to a cer-
tain degree when employed in fedcntary ma-
nutafturcs, or from living in crowded houfes, or
in the narrow lanes of large cities ; whereas
they improve in their oature and conftituiion in
moft of the country labours which are carried
on in the open air.

Organization, fcnfation, fpontaneous motion,
and ail the opcmtions of life, only exift at the
furface of the earth, and in places expofed to the
influence of light. Without it nature itfelf would
be lifulefs and inanimate. By means of light,
the benevolence of the Deity hath filled the
furface of the earth with organization, fenfation,
and intelligence. The fable of Promotheus
might perhaps be confidered as giving a hint of
this philofophical truth, which had even pre-
fented itfelf to the knowledge of the ancients.

I have intentionally avoided any difquilitions

relative to organized bodies in this work, for

which

K-

Utioo.
old Names.

caowa
cnown

irbc

>lp^

lOfp'

"'^hloglflicaied
larine a.cid

liiti

OF CHEMISTRY. 255

which reafon the phenomena of refpiration, £ui«<i
guification, and animal heat, are not confidered ;
but I hope, at fome future time, to be able to
elucidate tbefe curious fubjedts.

S£CT. IV. — Ob/ervations upon the Combinations
of Oxygen with tbejimple Subjlances.

Oxygen ferms almoft a third part of the maft
of our atmofpbere, and is confequently one of
the mofl plentiful fiibftances in nature. All
animals and vegetables live and grow in this
immenfe magazine of oxygen gas, and from it
we procure the greateft part of what we employ
in experiments. So great is the reciprocal af.
finity between this element and other fubftances,
that we cannot procure it entirely difengaged
&om combination. In the atmofphere it is uni*
ted with caloric, in the ftate of oxygen gas, and
this again is mixed with about twice its weight
of azotic gas.

Several conditions are requifite to enable a
body to become oxygenated, or to permit oxy-
gen to enter into combination with it. In the
firft place, it is necefiary that the particles of
the body to be oxygenated (hall have lefs reci-
procal attradion with each other than they
have for the oxygen, which otherwife cannot
poflibly combine with them. Nature, in this
cafe, may be aflifted by art, as we have it in our

power

ELEMENTS

power to diminifli the attra&ion of the parti-
cles of bodies, almoll at will, by beating them,
or, in other words, by introducing caloric into
the iiitcrflices between their particles ; and, as
the attraction of thefe particles for each other
is diminidied in the invcrfe ratio of their dif-
tance, it is evident that there muil be a certain
point of diftance of particles when the affinitT"
they poffefs with each other becomes lefs than
that xhe^ have for oxygen, and at which oxy-
genation niuft' necefliirily take place if oxygen
be prefent.

We can readily conceive, that the degree of
heat at which this phenomenon begins muft be
diAcrcnt in different bodies. Hence, on pur-
pofe to oxygenate mofl; bodic?, efpecially the

OF CHEMISTRY. 257

rapid ; and the oxygenation of lead, tin, and moft
of the metals, takes place vaftly flower, and
confequently the difengagement of caloric, and
more efpecially of light, is hardly fenfible.

Some fubftances have fo ftrong an affinity for
oxygen, and combine with it in fuch low de-
grees of temperature, that we cannot procure
them in their unoxygenated ftate ; fuch is the
muriatic acid, which has not hitherto been
decompofed by art *, perhaps even not by na-
ture, and which confequently has only been
found in the ftate of acid. It is probable that
many other fubftances of the mineral kingdom
are necefliarily oxygenated in the common tem-
perature of the atmofphere ; and that, being al-
ready faturated with oxygen, their farther aftion
upon that element is thereby prevented.

There are other means of oxygenating fimple
fubftances, befides expofure to air in a certain
degree of temperature ; fuch as by placing them
in contaft with metals combined with oxygen,
and which have little affinity with that element.
The red oxyd of mercury is one of the beft fub-
ftances for this purpofc, efpecially with bodies
which do not combine with that metal. In this
oxyd the oxygen is united with very little force

R to

* The real or fuppofed dilcovery of the bafe of this
apid has been mentioned in (bme former notes.— -T.

»58

ELEMENTS

to tbe metal, and can be driven out by a degree
of heat only fufficient to make glafs red hot ;
wherefore, fuch bodies as are capable of uniting
with oxygen are readily oxygenated, by ^eans
of being mixed with red oxyd Qf mercury, and
then moderately heated. The fame effed may
be, to a certain degree, produced by means of
the black oxyd of mangauefe. the red oxyd of
lead, the oxyds of filver, and by moftof the me-
tallic oxyds, if we only take care to choofe fuch
as have lefs affinity with oxygen than the bodies
they are meant to oxygenate. AU the metallic
redudions and revivifications belong to this clafs
of operations, being nothing more than oxy-
genations of carbon, by means of the feve-
ral metallic oxyds. The carbon of the char-

OF CHEMISTRY. 259

eittiMme caution^ and only with very fmall quan*
titles ; becaufe, as the oxygen enters into the
compofition of nitrats^ and more efpecially of
oxygenated muriats, combined \tith almofl as
much caloric as is neceflary for converting it
into oxygen gas, this immenfe quantity of calo-
ric becomes fuddenly free, the inftant of the com-
bination of the oxygen with the combuftiblc bo-
dy, and produces fuch violent explofions as are
perfedly irrefiftible.

By the humid way we can oxygenate moil
combuftible bodies, and convert moft of the
oxyds of the three kingdoms of nature into acids.
For this purpofe we chiefly employ the nitric
acid, which has a very flight hold of oxygen, and
quits it readily to a great number of bodies, by
the afliftance of a gentle heat. The oxygenated
muriatic acid may be ufed for feveral operations
of this kind, but not in them all.

I give the name of binary to the combinations
of oxygen with the Ample fubftances, becaufe in
thefe only two elements arc combined. When
three fubftances are united in one combination I
call it ternary ; and quaternary when the combi-
nation confifls of four fubftances united.

R % Table

i6o

ELEMENTS

Table of the Combinations of Oxygen with the Com-
pound Radicals.

Naniti of the Ra' Naaut of the rtfulting Acids,

dicati. Nttti Nomenclalure. UM NomtncUturt,

NUro-muriaUt
radical

■ i Nitro-muriadc acid

Aqua regia.

Tartaric

Tanarous acid

Unknown tiU lately.

Malic

Malic acid

Ditto.

Citric

Citric acid

Acid of lemons.

Pyro-lignous

Pyro-lignous acid

C EmpyreUmatic acid of
}_ wood.
Empyr. ^id of fugar.

Pyro- mucous

Pyro-macousacid

Pyro-tartaroua

1 Pyro-tartarous acid

Empyr. acid of tartar.

Oxalic

Oxulic acid

Acid of forrel.

Acetic

f Acetous acid

'Vinegar, or acid of
. vinegar.

1. Acetic acid

_ Radical vinegar.

Succinic

Succinic acid

Volatile fall of amber.

Benzoic

Be u zoic acid

Flowers of benzoin.

Camphoric

Camphoric acid

Unknown till lately.

OF CHEMISTRY- 261

Sect. V. — Obfervations upon the Combinations of
Oxygen ik)itb the Compound Radicals.

I publilhed a new theory of the nature and
formation of acids in the Memoirs of the Aca-
demy for 1776, p. 671. and 1778, p. 535. in
which I concluded, that the number of acids
muft be greatly larger than was till then fup-
pofed. Since that time, a new field of inquiry
has been opened to chemifts ; and, inftead of
five or fix acids, which were then known, near
thirty new acids have been difcovered, by which
means the number of known neutral falts have
been incrcafcd in the fame proportion. The
nature of the acidifiable bafes, or radicals of the
acids, and the degrees of oxygenation they arc
fufceptible of, flill remain to be inquired into.
I have already fliown, that almoft all the oxy-
dable and acidifiable radicals from the mineral
kingdom are fimple, and that, on the contrary,
there hardly exifts any radical in the vegetable,
and more efpecially in the animal kingdom, but
is compofed of at leafl two fubllances, hydro-
gen and carbon, and that azot and phofphorus
are frequently united to thefe, by which we have
compound radicals of two, three*, and four bafes
or fimple elements united.

R 3 From

ELEMENTS

From tlicie oblervations, it appears that the
vciTL-tiiblc snd animal osyds and acids may dif-
fer from each other in three feveral ways ; ac-
c-ordin;; to the number of Ample acidifiable ele-
TDcntf of which their radicals are compofed ;
arcsrding to the proportions in which thefe
arc combined together ; and according to their
different degrees of oxygenation : Thefe circum-
HiTicei are more than fufficicnt to explain the
grejt %-aricty which nature produces in thefe
fubi^anccs. It is not at all furprifing, after thi^
that moft of the vegetable acids are convertible
into each other ; nothing more being reguiftte
tor this purjwfe, than to change the propor-
tions of the hydrogen and carbon in their com-

d5* CHElVflStRt.

263

fubjed : For, although the oils appear to be
formed of nothing but hydrogen and carbon, we
do not know if thefe are in the precife proportion
neceiTary for conftituting the radicals of the acids ;
and, fince oxygen enters into the compofition of
thefe acids equally with hydrogen and carbon^
there is no more reafon for fuppoGng them to bd
compofed of oil rather than of water or of carbo-
nic acid. It is true that they contain the mate- .
rials neceflary for all thefe combinations, but
then thefe do not take place in the common tem-
perature of the atmofphere ; all the three ele-^
ments remain combined in a ftateof equilibrium^
which is readily deftroyed by a temperature on«
ly a little above that of boiling water *.

R4

Tabibi

* See Fart I. Chap. XIl. upon this Subjea— A<

204

ELEMENTS

I

Table of the Binary Combinations of Aztit with
ibe Simple Subjtances.

Simpit
Subfiances

Caloric

Hydrogen

Oxygen

Refuki of tht Combinations.
Ntta Nomtnclatvre. Old Nomenciaiurt.

: gas, or

Azogas^JI''"'?'"'""''^

i_Mephiti

Ammoniac, Ammooa Volatile alkali,

r Nitrous oxyd Bafe of nitrous gas.

I Nitrous acid Smoaking nitrous acid,

j Nitric acid Pale nitrous acid.

LOxygcnated nitricacid. Unknown.
f This combinadoD is hitherto unknown ; lliould it
I ever be dil'covered, it will be called, according
^ to the principles of our nomenclature, Azuret
J of Carbon. Csrbon difToIves in a7.otic gas, and
L forms carbonated azotic gad.

Azuret of phofphorm. Still unknown.

Az4jret of Sulphur Still unknown. We know
that fulphur dilTulves in aiotic gas, forming

OF CHEMISTRY. 26:

Sect. VI. — Obfervations upon the Combinations
of Azot with the Simple Subjlances.

AzoT is one of the moft abundant elements :
combined with caloric it forms azotic gas, or
mephitis, which compofes nearly two-thirds of
the atmofphere. This element is always in the
ftate of gas in the ordinary preffure and tempe-
rature, and no degree of compreffion or of cold
has been hitherto capable of reducing it either
to a folid or liquid form. This is likewife one
of the eflential conftituent elements of animal
bodies in which it is combined with carbon and
hydrogen, and fometimes with phofphorus ;
thefe are united together along with a certain
portion of oxygen, by which they are formed
into oxyds or acids, according to the degree of
oxygenation. Hence the animal fubftances may
be varied, in the fame way with vegetables, in
three different manners ; according to the
number of elements which enter into the com-

pofition

more diftinft from other terms : the French terms Azure,
Sulphure, Phofphure, are not fufTiciently diflinguilhable in
Englifh, from Azure, a colour, Sulphur, and Phofphor,
which is fometimes ufed for Phofphorus ; but Azuret,
Sulphuret, Carburet, and Phofphuret, which are tranflated
from Azuretum, Sulphuretum, Carburetum, and Phof*
- phoretum, both anfwer the purpofe of the new nomencla-
ture completely, and run no hazard of occafioning any
miAake. — T.

ELEMENTS

p.-:i:i>-n ctxhs bafc or radical ; according to the
priiPiiriioi) of thefe elements ; and, according to
the degrees of oxygenation.

When combined with oxygen, aiot forms
the nitrous and nitric oxyds and acids, when
with hydrogen, ammoniac is produced. Its com-
binations with the other fimple elements arc ve-
ry little known ; to thefe we give the name of
Azurets, preferving the termination in uret for
all unoxygenated compounds. It is extremely
probable that all the alkaline fubflances may
hereafter be found to belong to this genus of a-
zurets.

The azotic gas may be procured from atmo-
fpheric air, by abforbing the oxygen gas which

OF CHEMISTRY. 267

mixed with carbonic aci/i gas, which may be
abforbed by a folution of caullic alkali, or by
lime-water, after which the azotic gas remains
pure. We can procure it in a fourth manner
from combinations of ammoniac with metallic
oxyds, as pointed out by Mr de Fourcroy : The
hydrogen of the ammoniac combines with the
oxygen of the oxyd, and forms water, while the
azx>t being left free efcapes in form of gas.

The combinations of azot were but lately dif*
coyered : Mr Cavendifh firft obferved it in ni-
trous gas and acid, and Mr BerthoUet in ammo-^
niac and the pruffic acid. As no evidence of
its decompofition has hitherto appeared, we are
fully entitled to confider azot as a fimple ele-
mentary fubllance.

Tabu

ELEMENTS

:.V Eir.arv Combinations of Hydrogen with
Simple Subjlances.

Sirrtple HtfuUin^ Compounds,

Subjlmces. AVtt Nommchturt. Old Natnei.

Caloric Hjdrogen gas Inflammabte air,

AzM Aiumoniac Volatile alkali.

OxygcB Water Water.

Sulphur J Hjdmret of fulphur, or "J

I fulphuret of hydrogen / jj.^^^^^ ^^^^oy,n '.
Phofphorus S ^J"!™;';' °^ Phofphorus, or f

) pholphuret oi hydrogen J
C.rbo» JHydro-earbonou., or car. ? Notkaow.ullkKly.

bono-hydrous radicals f j ■'

OF CHEMISTRY. 269

Sect. VII. — Obfervations upon Hydrogen^ and
its Combinations with Simple Subjiances.

Hydrogen, as its name expreffes, is one of the
conftituent elements of water, of which it forms
fifteen hundredth-parts by weight, combined
with eighty-five hundredth-parts of oxygen.
This fubftance, the properties and even exiftencc
of which was unknown till lately, is very plen-
tifully diftributed in nature, and adls a very con-
fiderable part in the proceffes of the animal and
vegetable kingdoms. As it poffefles fo great
affinity with caloric as only to exift in the (late
of gas, it is confequently impoffible to procure
it in the concrete or liquid ftate, independent of
combination.

To procure hydrogen, or rather hydrogen
gas, we have only to fubjed: water to the adtion
of a fubftance with which oxygen has a greater
affinity than it has to hydrogen ; by this means
the hydrogen is fet free, and, by uniting with
caloric, afliimes the form of hydrogen gas. Red
hot iron is ufually employed for this purpofe :
The iron, during the procefs, becomes oxy-
dated, and is changed into a fubftance relem-
bling the iron ore from the ifland of Elba. In
this ftate of oxyd it is much lefs attradible by

thQ

a7o

ELEMENTS

the magoet, and diflblves in acids without eSer.
vefccnce.

Charcoal, in a red heat, has the fame power
of decompofing water, by sttrafting the oxjgen
from its combination with hydrogen. In this
prjcefs carbonic acid gas ii formed, and mixes
with the hydrogen gas, but is eafily feparated
by means of water or alkalies, which abforb the
carbonic acid, and leave the hydrogen gas pure.
IVe may likewife obtain hydrogen gas by dif-
fotring iron or zinc in dilute fulphuric acid.
The two metals decompofe water very flowly,
and with great difficulty, when alone, but do it
with great eafe and rapidity when affifted by ful-
phuric acid ; the hydrogen unites with caloric
during the procefs, and is difengaged in form

OF CHEMISTRY.

271

We muft always recur to the examination of this
queftion, " Are the heat and light, which arc
difengaged during the different fpecies of com«
buftion, fumifhed by the burning body, or by
the oxygen which combines in all thefe opera-
tions ?" And certainly the fuppolition of hydro-
gen being difengaged throws no light whatever
iipon this queftion. Belides, it belongs to thofe
who make fuppofitions to prove them ; and,
doubtlefs, a dodrine which without any fuppoli-
tion explains the phenomena as well, and as na-
turally, as theirs does by fuppofition, has at Icaft
the advantage of greater limplicity *.

Table

* Thofe who wi(h to fee what has been (aid upon this^
great chemical queftion by Meff. de Morveau, BerthoHer,
De Fourcroy, and myfelf, may confult our tranflation of
Mr Kirwan's £flay on Fhlogifton.— A«

ELEMENTS

jilW^

iU/^ajCtmp^w,di.

^M^Lm^s.

yrv .Vi

Cliunc

Suiphoric gu

-Osyd of fnlphor Soft folphnr.

OiTgea

jolphurons acid Solphnreoos acid.

.Su.fdiuric acid Vitriolic acid

H7*Dg«i

aolpharctofhjdrogen f

Axat

azot J Uokoowa Comlii.

Phorphonia

phofphorus ' natioDS.

Cubon

carbon L

Anomaaj

antimoD/ Cmde antimooy.

SUver

Over

Arfenic

•r&nic OrptmeDt. tcalnr.

Biimuth

bifmuth

Cobalt

cobalt

Ccpp«

copper Copper pyrile».

Tin

tin

Iron

iroa Iron pyrites.

Manganefe

manganefe

Mercury

—y ^^'iSJ""*

MolvbdcRB

molybdena

OF CHEMISTRT. ajf^

Sect. Yllh-^Ofirvaiions vn Sulphur and iu

CombinatioflSi

Sulphur is a combuftible fubflance, having a
very great ttbAtacy to combination ; it is Na-
turally in a folid ftate in the ordinary tc»ifi{>ef)M
ture, and rtqaites a beat fomewhat higher than
that of boiling; • water to nlake it liquify. Sul-
phur is formed by nature in k confiderable de^
gree of puri^ in ike neighbourhood of vdlca^
nod ; w^ find if lik^wlfe, chiefly in the ft^te tff
fulphuric aeid, combined with argill in aluitiinoul
fchiftusy with lime in gypfum, &c. From thefi^
combinations it may be pi^ocured in the ilate of
fulphur, by carrying off its oxygen by means of
charcoal in a red heat ; carbonic acid is fotm^
ed, and efcapes in the (late of gas ; the fulphut
remains combined with the clay, lime. Sec. in
the ftate of fulphuret, which is decorapofed by
acids ; the acid unites with the earth into a neu-»
tral fait, and the fiilpbuy n precipitated^

Tabli

*74

ELEMENTS

Table of the Binary Combinations of Phofphoruj
with the Simple Subftaacei.

Simple Svbfianett.

Caloric

Oxygen - -

Hydrogen - -

Axot

Sulphur - -

Carbon

Metallic Subllances

Potaih - -

Soda - -

Ammoniac

/ttfiJHirf ComfomnA.

Pbofphoric gas.
r Oxyd of phofphorus.

Pbofphorous acid.
L Pbofphoric acid.

Fhofphuret of bydrogen.

Phoqiburet of azot.

Fhofphuret of Sulphur.

Phofpbaret of carbon.

Fbofphurets of metals *.

OjT chemistry. 175

SjECT. IX. — ObfervaHons on Pbojpborus^ and its
Combinations.

Phdfphorus is ^ fimple combultible fubftance,
which was unknown to chemifts till 1667, when
it was difcovered by Brandt, who kept the pro-
cefs fccret j foon after Ktinkel found out Brandt's
method of preparation, and made it public. It
has been ever flnce known by the name of Kun-
kePs phbfphorus. It was for a long time prci-
cured only from Urine ; and, though Homberg
gave an account of the procefs in the Merafaijrs
of the Academy for 1692, all the philofophefs
of Europe were fuppUed with it from England.
It was firft made in Francfe in 1737, before a
committee of the Academy at the Royal Garden.
At prefent it is procured in a more commodious
and more economical manner from animal bones,
which are real calcareous phofphats, according
to the proceffes of Meffrs Gahn, Scheele, Rou-
elle, &c. The bones of adult animals, being
calcined to whitenefs, are pounded, and pafled
through a fine filk lieve j upon the fine pow-
der a quantity of dilute lulphuric acid is pour-
ed, lefs than is fufficient for diifolving tbje whole.
This acid unites with the calcareous earth of the
bones into a fulphat of. lime, and the phofpho-
lic acid remains free in the liquor. The liquid

S2 .is

27C

ELEMENTS

is decanted off, and the reflduum walhed vitb
boiling water ; this water which has beea ufed
to wafli out the a^ering acid is joined with
what was before decanted off, and the whole ii
gradually evaporated ; the dilToIved fulphat of
lime cryftallizes in form of filky threads, which
are removed ; and, by continuing the vvapora-
tion* we procure the phofphoric add, under the
appearance of a white peUucid glafs. When thii
is powdered, and mixed with one third its weight
of charcoal, we procue very pure phofphorus.
by fubUmation *. The phofphoric acid, as pro-
cured by the above proceb, is never fo pure as
that obtained by oxygenating pure phofphorus,
either by combuftion or by means of nitric acid ;
wherefore this latterfltould always he employ-

OF CHEMISTRY.

a;;

cf animal analyfis. In all thefe it is nfually
combined with carbon, hydrogen, and azot,
forming very compound radicals, which are, for
the moft part, in the ftate of oxyds, by a firft
degree of union with oxygen. The difcovery
of Mr Haflenfratz, of pbofphorus being contain-
ed in charcoal, gives reafon to fufpei^ that it is
more common in the vegetable kingdom than
has been generally foppofed : It is certain, that
by proper procefles, it may be procured from
every indiridual of fome of the families of plants.
As no experiment has hitherto given reafon to
fufped that phofphorus is a compound body, I
have arranged it with the fimple or elementary
fubftances. It takes fire at the temperature of
104* of the thermometer^, ^^

Tablx nf the Binary Combinations of Carbon.

Simfik
Subftances.

Oiygen

Sulphur

Phofphorus

Azoc

Hydrogeu

Metallic Sub-
ftances

Alfcalietand
e«tbf

Ri/ubing
New Nofmnclaiure.
C Ozyd of carbon
\ Carbonic acid
Carburet of fulphnr *>
Carburet of phofphorus i* Unknown.
Carburet of azot J

C Garbono-bydrous radicals
I, Fixed and volatile oils

Compounds*

Old Nanus*
Unknown.
Fixed air, chalky acid.

J Carburets of the fe veral
metals

Of thefe only the car-
burets of iron and
zinc are known, and
were formerly call-
ed Plumbago.

\ Carburet of pptalh, Sec Vtduiown.

S3

Sect.

278

ELEMENTS

Sect. X. — Obfervations upon Carbon, and its Com-
binations tuitb Simple Subftances,

As carbon has not been hitherto decompo-
fed, it muft, in the prefent Hate of our know-
ledge, be confidered as a limple fuhftaoce. By
modern experiments it appears to exift ready
formed in vegetables ; and I have already re-
marked, that, in thefe, it is combined with hy-
drogen, fometimes with azot and phofpborus,
forming compound radicals, which may be
changed into oxyds or acids, according to their
degrees of oxygenation.

To obtain the carbon* contained in veceta-

OF CHEMISTRY. 279

t)r changes into gas, all the parts of the body
ftifceptiblc of combining with caloric into that
form ; and the carbon, being more fixed in its
nature, remains in the retort, combined with a
little earth and fome fixed falts, in the form ge-
nerally known by the name of charcoal.

In the bufinefs of charring wood, this is done
by a lefs expenfive procefs. The wood is dif-
pofed in heaps regulariy arranged, and covered
wit^ earth, fo as to prevent the accefs of any
more air than is abfolutely neceflary for fiipport-
ing the fire, which is kept up till all the water
and oil is driven off, after which the fire is ex-
tinguifhed by (hutting up all the air-holes.

We may analyfe charcoal either by combuftion
in air, or rather in oxygen gas, or by means of
nitric acid : In either cafe we convert its pure
carbon into carbonic acid ; and fometimes a
little potalh and fome neutral falts remain. This
analyfis has been hitherto but little attended to
by chemifts ; and we are not even certain if pot-
afli exifts in charcoal before combuftion, or whe-
ther it be formed by means of fome unknown
combination during that procefs.

Sect. XI. — Obfervations upon the Muriatic, Flu-
oric^ and Boracic Radicals, and their Combina-^
tions.

As the combinations of thefe fubftances, ei-
ther with each other, or with the other combuC-

S4 tible

»»o

ELEMENTS

tible bodies^ are hitherto entirely unknowD, we
)iare not attempted to form anj table for their
nomcQclature. We only )cnow that tbefe r^-
cals are fufceptible of oxygeoatioD, and of form-
JDg the muriatic, fluoric, aod boracic acids : and
that, in the acid ftatc, thej enter into a number
of combinations, to be afterwards detailed. Che-
piiftry has hitherto been unable to difoxjge-
nate any of them, fo as to eiihibit th?m in a
fimple ftate. For this purpofe, fome ftibftance
muft be employed, to which oxygep has a ftrong-
er affinity than to their radicals, either by means
of fiogle affinity, or by double eledive attrac-
tion. All that is known relative to the origin
of the radicals of thefe acids, will be mentioned
the fct^lions fct apart for conlidering their

OF CHEMISTRY.

28Z

ttece0*ary to be mentioned is, that thefe alloys
fhould be named according to the metal in Ibe-
geft proportion in the mixture or combinatioa ;
thus the term ailoy <^£old andJUvtr, or gold al-
loyed with filver, indicates that gold is the pre-
dominating metal.

Metallic alloys, like all other combinations,
have a point of fiituration ; it would even ap-
pear, &om the experiments by Mr de la Briche,
that they have two pcrfedly diftindl degrees of
^turation.

Tasle

ELEMENTS

Tabls <^ the Comhinatioiu qf Azot, in the fiate of M'-
trous ^icid, with the Salifiable Safes, arranged accord-
ing to tbe Affinities of tbefe Bafes vdtb the Acid.

tftmiti of tbe

Bafti.
Bujtci

pQulk
Soda

lime
MagncliK
Ammoniac
ArgiU

Oxji of xinc
iron

mnnganefe
cobalt

Names of the Neutral Sa&t.
Neut NomeneUuurt,
Nitrite of barytes.

Notes.

foda.
lime,
magnefia.

argill.

Zinc.
iroD.
mganefc

Tbde bits are on-
ly knowD of late, aod
■ have received no par-
ticular names io the old
nomcnduure.

As TOttak diffolve
both in niuous and
nitric acids, metallic
falls muft of confe-
qiicDce be formed ha-
ving diiferent degree*
'cnatiou. I'tiofe

OF CHEMISTRY.

283

Table of tht Combinations of ji^ot^ completely faiuraied with
Oxygen^ in tbejiate of Nitric Acid^ with the Salifiable BafeSf
in the Order of their Affimty with that Acid.

Ba/ci.
Barjtes

PoteQi

Soda
Strontites

Lime

Magnefia
Ammoniac

Argill

Oxyd of zinc
iron

New Nomenclature.

Nitrat of barytes
pota(h

foda
ftrondtes

lime

manganefe

cobalt

nickel

lead

tin

copper

bifmuth
antimony
arfenic
mercury

filver

gold
platina

ammoniac

Names of the refijting Neutral Saits.

Old Nomenclature,

C Nitre, with a bafe of
C heavy earth.
Nitre, faltpetre. Nitre
with bafe of potafli.
Quadrangular nitre.
Nitre with bafe of
mineral alkaK.
Unknown.

{Calcareous nitre. Ni-
tre with calcareous
bafe, Mother- water of
nitre, or of faltpetre.
^ ^ Magneiian nitre, Nitre
^ C with bafe of magnefia.
Ammoniacal nitre.
Nitrous allum. Argil-
laceous nitre. Nitre
with bafe of earth of
alum.
Nitre of zinc.
Nitre of iron, Martial
nitre. Nitrated iron.
Nitre of manganefe.
Nitre of cobalt.
Nitre of nickel.
S Saturnine nitre, Nitre
^ of lead.

Nitre of tin.
S Nitre of copper, or of
*• Venus.
Nitre of bifmuth.
Nitre of antimony.
Arfenical nitre.
Mercurial nitre*
C Nitre of filver, or of
2 luna, Lunar Gauftic«
Nitre of gold.
Nitre of platina.

fcCT.

argill

zinc

iron

{

manganefe

cobalt

nickel

lead.

tin

copper

bifmuth
antimony
arfenic
mercury

filver

gold
platina

*H

:L£H£NrS

Sect. X.Ul.—(^/crvatiotu i^r tbe Nitrous aad
Nitric Aeidt, aad tbeir Cambiaationt.

The nitrous and nitric acids are procured
liom a neutral fait long known in the arts un-
der the nanie of ya/f^tr«. This fait is extraded
by lixiriation from the rubbilhof old buildings,
from the earth of cellan, ftables. or barns, and
in general of all inhabited places *. In thefe
earths the nitric acid is ufually combined with
lime and magnefia, fometimes with potafb, and
rarely with argill. As all thefe falts, excepting
the nitrat of potafli, attrad the moifture of the
air, and conl'equently would be difficultly

OF CHEMISTRY. 285

petre are decompofed hy means of one part of
concentrated fulphuric acid, in a retort with
Woulfes' apparatus, (PL IV. Fig. i.) having
Its bottles half filled with water, and all its
joints carefully luted : The nitrous acid pafles
over in form of red vapours furcharged with ni-
trous gas, or, in other words, not completely
faturated with oxygen. Part of the acid con-
denfes in the recipient, in form of a dark o-
range red liquid, while the reft combines with
the water in th£ bottles*, During the diftilla-
tion, a large quantity of oxygen ga^ efcapes,
owing to the greater affinity of oxygen to calo-
yIc, in a high temperature, than to nitrous acid,
though in the ufual temperature of the atmo-
fphere this affinity is reverfed. It is from the
dlfengagement of oxygen that the nitric acid
ef the neutral fait is in this operation converted
into nitrous acid *• It is . brought back to the
ftate of nitric acid by heating over a gentle fire,
which drives off the fuperabunda^t nitrous gas,
and leaves the nitric acid much diluted with

water.

Nitric

• It is evideDt, that in this operation, there is a Very
great lols of nitric acid \ as, from the difengagemeot of
oxygen, we cannot poi&bly procnre near the fame quan-
tity of nitric acid by diftillationy that exiiled in the com-
bined fiate in the nitre, — T,

I ■

286

ELEMENTS

Nitric acid is procurable in a more concen-
trated ftate, and with much lefs lofs, hy mixing
■very dry clay with faltpetre. This mixture
is put into an earthen retort, and dilUlled with
a ftrong fire : The clay combines with the pot-
afli, for which it has great affinity, and the nf-
tric acid pafles over, flightly impregnated with
nitrous gas. This is eafily difengaged by heat-
ing the acid gently in a retort, a fraall quantity
of nitrous gas pafles over into the recipient, and
very pure concentrated nitric acid remains in the
retort.

We have already feen, that azot is the nitric
radical. If to 2d~ parts by weight, of azot,
43-|- parts of oxygen be added, 64 parts of ni-
trous gas are formed ; and, if to this we join 36

OF CHEMISTRY. ^87

acid, and not the nitric, that circumftance ex<
plains in fome degree the difference in the re--
fults of our experiments. ^

AS| in all experiments of a philofophical na-
ture, the utmoft poffible degree of accuracy is
required, we mult procure the lutric acid for
experimental purpoTes, from nitre which has
been preyioufly purified from all foreign mat-
ters. If, after diftillation, any fulphuric acid h
fufpedled in the nitric acid, it is eafily feparated
by dropping in a Jittle nitrat of barytes, fo long
as any precipitation takes place ; the fulphuric
acid, from its greater affinity, attrads the bary-
tes, and forms with it an infoluble neutral fait,
which falls to the bottom. It may be purified
in the fame manner from muriatic acid, by drop-
ping in a little nitrat of filver, fo long as any
precipitation of muriat of filver is produced.
When thele two precipitations are finiihed, dif-
til off about feven- eights of the acid by a gentle
heat, and what comes over is in the mod perfedi
degree of purity.

The nitric acid is remarkably prone to com-
bination, and is at the fame time very eafily
decompofed. Almoft all the fimple fubftances,
with the exception of gold, filver, and platimi^
rob it lefs or more of oxygen ; fome of them
even decompofe it altogether. It was very an-
ciently known, and its combinations have been
more ftudied by cheraifts than thofe of any o-

ther

388 ELEMENTS

ther acid. Thefe combinations were :
nitres by Mefln Macquer and Beaume ; but we
have changed their names to nitrats and nitrites^
sccordiog as they are formed by nitric or by ni-
trous acid, and have added the fpecific name of
each particular bafc, to diftinguifh the feverol
combinations from each other.

Tablc

OF CHEMISTRY.

289

Table of the Combinations of Sulphuric Acid with
the Salifiable Bafcs^ in the order of Affinity.

Nanus of the Btfis.

New NometKUuwre.

Barytes Solphat of barytes
Strontites firontius

Pota&

pocaili

Soda

foda

Lime

lime

Magnefia

magnefia

Ammoniac

ammoniac

ArgiU

argill

Oxjd of mc

zinc

iron

iron

mangande

oobak

nickel

lead

tin

manganeie

cobalt

nickel

lead

tin

copper

bi£muth

antimony

arfenic

mercary

filver

gold

platina

copper

bifmoth

antimony

arfenic

mercury

filver

gold

platina

T

Rejmlting Compounds.
Old Nomenclature.

{Heary fpar, Vitriol of
heavy earth.
Unknown*
rVitridated tartar, Sal
^ de duobusi Arcanom
L duplicatum.
Glaober's fait.

{Selenite, gypium, cal-
careous vitriol.
cEpfomfalt, SedlitzfSUr,
\ Magnefian vitriol.

i Glauber's iiBcret fal am-
moniac.
Alum,
r White vitrid^ Goilar vi-

< trioly White coperas,
L Vitriol of zinc.

f Green coperas, Green
^ vitriol,Martial vitriol^
L Vitriol of iron.

Vitriol of manganeie.

Vitriol of cobalt.

Vitriol of nickeL

Vitriol of lead.

Vitriol of tin.
rBlue coperas. Bine vi«

< triol, Roman vitriol,
L Vitriol of copper.

Vitriol of bifmuth.
Vitriol of antimony.
Vitriol of arfenic
Vitriol of mercury-
Vitriol of :fi]ver.
Vitriol of gold.
Vitriol of platina.

Sect.

ELEMENTS

Sect. XIV, — Obfervations upon Sulphuric Acid,

and its Combinatiom.

Yox a long time this acid was procured by
diflillation from fulphat of iron, in which ful-
phiiric acid and oxyd of iron are combined,
according to the procefs defcribed by Bafil Va-
lentine in the fifteenth century ; but, in mo-
dern times, it is procured more economically
by the combuftion of fulphur in proper veflels.
Both to fucilitatc the combuftion, and to aflift
the oxygenation of the fulphur, a little powder-
ed faltpetre, or nitrat of potalh, is mixed with
it ; the nitre is decompofed, giving out its oxy-
gen to the fulphur, and contributes to its con-

OF. CHEMISTRY. api

torts with a gentle heat, jthe^ water paflcs ov-er,
(lightly impregnated with acid, and the fulphu-
ric acid remains behind in a concentrated ftate.
It is then pellucid, without any flavour, and
nearly double the weight of an equal bulk of
water. This procefs would be greatly facili-
tated, and the combuftion much prolonged, by
introducing frefh air into the chambers, by means
of feveral pairs of bellows direfted towards the
flame of the fulphur, and by allowing the ni-
trous gas to efcape . through long ferpentine ca-
nals, in contaA with water, to abforb any ful-
phuric or fulphurous acid gas it might contain.

By one experiment, Mr BerthoUet found tliat
69 parts of fulphur in combuftion, united with
31 parts of oxygen, to form 100 parts of ful-
phuric acid ; and, by another experinient, made
in a different manner, he calculates that 100
parts of fulphuric acid confift of 72 parts of ful-
phur, combined with 28 parts of oxygen, all by
weight.

This acid, in common with every other, can
only diffolve metals when they have been pre-
vioufly oxydated ; but moft of the metals are
capable of decompofing a part of the acid, fo
as to carry off a fufficient quantity of ox Vi^en,
to render themfelves foluble in the part 01 the
acid which remains undecompofcd. This hip-
pens with filver, mercury, iron, and zmc, in
-boiling concentrated fulphuric acid ; they be-

T 2 come

. ^ cpo&ig pate tf il

luriir M^oBraus sob gn*

^ .A lolUible in dSned fiil-

^ a^ harve doc fnlBcieot sf-

bu wHbBKSv it &DB its oom-

bc Upbar, the folphu-

a^^yJMgf; bot iroo and xioc,

ifif tte ■dioB «f tbe add, dccom-

I becooe oxjdtxei tt its «x-

t tbe be^ of facat.

H

TiJLI

OF CJtt£MlStRt.

*93

If ABLE of the Comhinaiionf of the Sulphurous A-
cid with the Salifiable BafeSf in the order qf
Affinity.

Names of tie BafeSk

Names of tie Neutral Salin

Barjtes

Sulphite of barjtes.

Potafti

potafh.
Ibda.

Soda

Lime

lime.

Magaefia

Aiagnefia.

Afnmoniac

^unmoniac*

Argill

wgilL

OKfd of ZlAC

^iiic«

iron

iron.

maoganefi^

mangaiiefe^
cobalt.

cobalt

nickel

tiickek

lead

lead.

tin

tin.

coppet

copper.

t^ifmuth

bifmutb.

antimony

antimony.

arfenic

atfenic.

tnercury

mercury*

filver

iilver.

gold

^ gold.

platina

platina.

T3

Sect*

^0/^— — -The only one of the/e falts known to the old
diemifis was the fulphite of Potaih, under the name of
Stabrsfulpbureottsfah: So that, before our new nomen-
clature, thefe compounds muft have* been named StabPs
fulphureos^s JaU^ having bale of fixed vegetable alkali)
and fo of the reft*

In this Table we have followed Bergman's order of a£5-
nity of the fulphuric acid, which is die fame in regard to
the earths and alkaliesy but it is not certain if the prder be
die £une for the metallic ozjds. — A.

ELEMENTS

Sect. XV. — Ob/ervatiotu upon Sulphurous Add,
and its Combinations.

The fulphurous acid is formed hy the union
of oxygen with fulphur, in a leffer degree of
o:;ygenation than the fulphuric acid. It is pro^
curable either by burning fulphur flowly, or by
diftitling fulphuric acid from iilver, antimony,
lead, mercury, or charcoal ; by thefe operations
a part of the oxygen quits the acid, uniting to
thefe oxydable bafes, and the acid palTes over
in the fulphurous flate of oxygenation. This
acid, in the common preflure and temperature
of the air, can only exilt in form of gas ; but it

OF CHEMISTRY. 195

not diflblve them, unlefs previoufly oxydated by
other means. From the fame principle it is
that the metallic oxyds diflblve without effer-
vefcence, and with great facility, in fulphurous
acid. This acid, like the muriatic, has even the
property of diflblving metallic oxyds furcharg-
ed with oxygen, and which are, confequently,
infoluble in fulphuric acid,. and in this way true
fulphats are formed. Hence we might be led
to conclude that there are no metallic fulphites^
were it not that the phenomena which accom-
pany the folution of iron, mercury, and fome
other metals, convince us that thefe metallic
fubftances are fufceptible of two degrees of oxy-
dation, during their folution in acids. There-
fore the neutral fait in which the metal is lead
oxydated muft be named fulpbite^ and that in
which it is fully oxydated muft be called yi//p6a/.
It is yet unknown whether this diftindion is ap->
plicable to any of the metallic fulphats, except
thofe of iron or mercury.

T 4 Table

£LEMENTS

r,v5-.s :f :bf Combinations of the Pbe^boretrj
Mu Ps«/^nc Acids with the SalifiabU Bufes^
i% w Order of Affinity,

Namet o/tht Ntvtral SaUtJhrmtdhf
Pb^bamuAeid. Pbe/pUeric Acii,

OF CHEMISTRY. 297

Sect, 'KVI.—Ob/ervationf upon Pbojpbcrous and
Pbojpboric Acids^ and tbar Combinations.

Under the article Phofphorus, Part II. Seft. IX.
we have already given a hiftory of the difco-
very of that fingular fubftance, with fome obfer--
vations upon the mode of its exiftenct^ in ve-
getable and aninial bodies. The bed method
of obtaining this acid in a ftate of purity is by
burning well purified phofphorus under bell-
glaflesy moiftened on the infide with diftilied
water ; during combuftion it abforbs twice and
a half its weight of oxygen ; fo that 1 00 parts
of phofphoric acid is compofed of 28^ parts of
phofphorus united to 71I parts of oxygen. This
acid may be obtained concrete, in form of white
flakes, which greedily attradl the moifture of the
air, by burning phofphorus in a dry glal^ over
mercury.

To obtain phofphorous acid, which is phofpho*
rus lefs oxygenated than in the ftate of phofpho-
ric acid, the phofphorus muft be burnt by a very
flow fpontaneous combuftion over a glafs funnel
leading into a chryftal phial ; after a few days,
the phofphorus is found oxygenated, and the
phofphorous acid, in proportion as it forms, at-
tratEls moifture from the air, and drops into the
phial. The phofphorous acid is readily changed
ihto phofphoric acid by expofurc for a long time
f to

298

ELEMENTS

to tht free air ; it abforbs oxygen from the air,
and bccoins fully oxygenated.

As pholphorus has a fufficient affinity for 0x7-
^n to attradt it from the nitric and oxygenated
nuiriutic acids, we may form phofphoric acid, by
mi-ans of thefe acids, in a very iimple and cheap
manner. Fill a tubulated receiver, half full of
concentrated nitric acid, and heat it gently, then
throw in fmall pieces of phofphorus through the
tube, thcfe are diflblved with efiervefcence, and
red fumes of nitrous gas fly off ; add phofphorus
fo long as it will diflblve, and then increafe the
fire under the retort, to drive off the laft parti-
cles of nitric acid ; phofphoric acid, partly fluid
and partly concrete, remains in the retort.

OF CHEMISTRY.

299

Table of the Combinations of Carbonic Acid^ wiib
the Salifiable Bafes^ in the Order of Affinity^

Names of the Bafts. Refubing Neutrai Salts.

Nnv Nomenclature, Old Nomenclature.

Barytes

Lime
Strontites

Fotafb
Soda

barytes

lime

flrontites

potafh
foda

Carbonats of * C Aerated or EfFerveicent heavj

\ earth.

i Chalk, Calcareous fpar.
Aerated calcareous earth.
Unknown.
rEiFervefcing or Aerated fixed
< vegetable alkali. Mephitis of
I. potafh.

{Aerated or Efiervefcing fixed
mineral alkali, Mephitic ibda.
r Aerated, efiervefcing, mild of
\ mephitic magnefia.
r Aerated, eflervefcing, mild or
1 mephitic, volatile alkali.

J Aerated or eflfervefcing argilla-
ceous earth, or Earth of alum.
rZinc fpar, Mephitic or aeni-
^ ted zinc.

c Sparry iron-ore, Mephitic oc
"i aerated iron.

Aerated manganefe.

Aerated cobalt.

Aerated nickel.
r bparry lead'^re, or Aerated
J lead.

Aerated tin.

Aerated copper.

Aerated bifmuth.

Aerated antimony.

Aerated arfenic.

Aerated mercury.

Aerated filver.

Aerated gold.

Aerated platina.

Sect.

• A$ thcfc falts have only been underflood of late, they
have not> properly fpcaking, any old names. Mr Morvcau, in
the Firft Volume of the Encyclopedia, calls them AUpbiies ^
Mr Bergman gives them the name of aerated ^ and Mr de
Fourcroy, who calls the carbonic acid chalky acid^ gives them
lie name of cbalks.^^Kn

Magnefia

magnefia

Ammoniac

ammoniac

ArgiU

argill

Oxyds of

zinc

zinc

iron

iron

manganefe

cobalt

nickel

manganefe

cobalt

nickel

lead

lead

tin

tin

copper
bifmuth

copper
bifmuth

antimony
arfenic

antimony
arfenic

mercury
filver
gold
platiDa

mercury
filver

plat ma.

'■•I

300

ELEMENTS

Sect. XVII. — Obfervationr upon Carbanic Aetd,
and its Combinations.

Of all the known acids, the carbonic is the
moil abundant in nature ; it exifts ready form-
ed in chalk, marble, and all the calcareou»
Hones, in which it is neutralized by a particu-
lar earth called lime. To difengage it from this
combination, nothing more is requifite than to
add feme fulphuric acid, or anj other which
has a flronger affinity for lime ; a briik eflfervef-
ceDce cnfues, which is produced by the difenga-
ged carbonic acid afluming the ftate of gas, im-
mediately upon being fet free. This gas, inca*
pable of being condenfed into the foUd or liquid
form by any degree of cold orof preffure hither-

OF CHEMISTRY. 301

this acid to Dr Black, before ivhofe time i^s pro-
perty of remaining always in the ilate of gas
had made it to elude the refearches of chemiftry.
It would be a mod valuable difcovery to fo-
ciety, if we could decompofe this gas by any
cheap procefsy as by that means we might ob-
tain, for economical purpofes, the immenfe
(tore of charcoal contained in calcareous earths,
marbles, limeftones, &c. This cannot be ef-
feded by fingle affinity, becaufe, to decompofe
the carbonic acid, it requires a fubflance as
combuftible as charcoal itfelf, fo that we (hould
only make an exchange of one combuftible bo-
dy for another not more valuable ; but it may
poffibly be acccomplifhed ^ by double affinity,
fince this procefs is fo readily performed by Na-
ture, during vegetation, from the moft common

materials.

Table

* Mr Smithfon Teanant has given, in the Phil. Tranf.
for 179I9 Art. XI. fomc experiments on the decompofi-
tion of carbonic acid. Some powdered marble, iligbtly cal-
cined, and fome phofphorus, being introduced into a g1a&
t^tbe coated -with a lute of {and and clay, are kept in a red
heat for fome minutes, and fufFered to cool ; on breaking
the tube, a black powder is found, which confifts of char-
coal and phofphat of lime. In the laboratory of Dr Black,
the decompoiition has been produced, via bumida; (bme
folution of fulphuet of potafli, thut had Mood for fr«
dajs in an open matrals, expofed to the air of '
vrhich had been breathed by feveral hundred
found to have depofited charcoal on the fid
fcl— T.

302 ELEMENTS

Tails ^f tht ComhimUlom of Muriatic Acid with tit
Saiifiahlt Bafts, at the Order of AJtnitjr.
Xamts of lie Rtfulling Neuira/ Saitt.

Bofi,.
Barytcs

Soda

Stionthes

Lime

Muriat of

{S«-(2lt hsviDg baft e£
hcftvy earth.
Febrifiige fait of S^lviu.

r Febrifiige fait of Sylviu*.
potalh \ Muriated vegetable fixed

C alkali.

foda
ftrontites

nagDcfia

S«a-laU.
Unknown.

ArgiU

argill

S Muriated Ume.
i Oil of lime.
5" Marine Epfbin fait.
1. Muriated magnclia.

Sal ammoniac.
C Muriated alum,
\ with bale of

Sea-laTt
earth of

alum.

Sea-falt of zinc, or Muri-
atic zinc.

Sail of iron, or Martial

OF CHEMISTRT.

Table oftbe Combinations of Oxygenated Muria-

tic Acid with the

SaHfiabie Safes, in the Order

of Affinity.

Noma oftht Niutrtd Salts fy

NamtiofthtBaJa.

tie Nevi Nomenclaturt.

Oxygenated murlat of

Barytes

barytes.

Potalh

potalh.

Soda

foda.

Lime

lime.

Magnefia

nagneiia.

ArgiU

argiU.

Oxyd of

ZIQC

zinc.

iron

iron.

manganefe

manganefe.

cobalt

cobalt.

nickel

nickel.

lead

lead.

tin

tin.

copper

copper.

bifmuth

bifmuth.

antimony

antimony.

arfenic

arfenic.

mercury

mercury.

filver

filver.

gold

gold.

platina i^lH

^^■HteinS'

Tlui order of falts, i
oiS^ wiB difcovered la 1786b

Sact.

^

ELEMENTS

Sect. XVIII. — Obfervations upon Muriatic and
Oxygenated Muriatic Acids, and tbeir Combi-

Muriatic acid Is very abundant in tb£ min&-|
ral kingdom, naturally combined with dlfienent J
falifiable bafes, efpecially with foda, lime, and
magnella. In fea-water, and the water of fc-
veral lakes, it is combined with thefe three ba-1
fes ; aiid in mines of rock-falt it is chiefly united
to foda. This acid does not appear to havefl
been hitherto decompofed in any chemical ex>l
periment*, fo that we have no idea whateveJ
of the nature of its radical, and only conclude,
from analogy with the other acids, that it con- '
tains oxygen as its acidifying principle, Mr Ber-
thollet fufpeds the radical to be of a metallic na-
ture ; but, as Nature appears to form this acid
daily in inhabited places, by combining miafmata
with aeriform fluids, this mufl necellarily f
a metallic gas to exill in the atmofphere, which ]
is certainly not impofiiblc, but cannot be
ted without proof.

* This fubjr3 hu been ftlready mentioned in foine fcvo
mer noi.i, Aherr thi- Intt difcovciy of this bafc a fud to ^
have beeo made by Dr Ginaniier^^T.

OF CHEMISTRY.

305

t

The muriatic acid has only a moderate ad-
herence to the falifiable bafes, and can readily
be driven from its combination uitli thele by
fulphuricacid. Other ;icids, as the nitric, for
inftance, may anfwer the fame purpole ; but ni-
tric acid being volatile, would mix, during di^it*
lation, with the muriatic. About one part of ful-
phuric acid is fufficient to dccompofe two parts of
decrepitated fea-falt. This operation is performed
in a tubulated retort, having Woulfe's apparatus,
PI. IV. Fig. I. adapted to it. When all the junc-
tures are properly luted, the fca-fak is put into
the retort, through tlie lube, the fulphuric acid
is poured on, and the opening is immediately
clofed by its ground cryftal Hopper. As tha
muriatic acid can only fubfift in the galTcous
form, in the ordinary temperature, we cannot
condenfeit without the prclcnce of water. Hence
the life of the water with which the bottles in
Woulfe's apparatus are half filled ; the muriatic
acid gas, driven off from the fea-falt in the retort,
combines with the water, and forms what the old
chemifls taWcdJhioaking/pirit t^f/all, or Glauber' f
Jpirit of/ea-fait, which we now name muriatic
acid.

The qcid obtained by the above procefs ii
ftiil capable of combining with a further quantity
of oxygen, by being diftilled from the oxyds of

Imanganefe, lead or mercury ; and the rcfulting
acid, which we name ox^^enaied muriatic acid,
U caa

ELEMENTS

Sect. XVIII. — Obfervations upon Muriatic and
Oxygenated Muriatic Acidj, and tbeir Combi-
nations.

Muriatic acid is very abundant in the mine-
ral kingdom, naturally combined with ditfetent
fali&able bafes, dpecially with foda, lime, and
magnefia. In fca-water, and the water of fe-
veral lakes, it is combined with thefe three ba-
fes ; aiid in mines of rock-falt it is chiefly united
to foda. This acid does not appear to have
been hitherto decompofed in any chemical ex-
periment*, fo that we have no idea whatever
of the nature of its radical, and only conclude^
from analogy with the other acids, that it con-
tains oxygen as its acidifying principle. Mr Ber-
thollct fufpeds the radical to be of a metallic na-
ture; but, as Nature appears to form this acid
daily in inhabited places, by combining miafmata
with aeriform Auids, this mufl neceflarily fuppofc
a metallic gas to exift in the atmofphere, which
is certainly not impoOible, but cannot be admit-
ted wittiout proof.

Tb

• This fuHii-a has been already menboned in Tome fi
nier non £, ■■■ nere ih. I^tt difcovtjy of ihif bafc is (ui b
bKVe'bMa mAde by Dr OiitB0DCT.->T.

M

OF CHEMISTRY. 305

Tbe muriatic acid has only a moderate ad-
herence to the falifiable bafes^ and can readily
be driven from its combination with thele by
falpharic acid. Other acids, as the nitric^ for
inftance^ may anfwer the fame purpofe ; but ni-
tric acid being volatile, would mix, during di(lil«
lation, with the muriatic. About one part of ful-
phuric acid is fufficient Co decompofe two parts of
decrepitated fea-falt. This operation is performed
in a tubulated retort, having Woalfe*s apparatus,
PL IV. Fig. I. adapted to it. When all the junc-
tures are properly luted, the fea-fait is put into
the retort, through the tube, the fulphuric acid
is poured on, and the opening is immediately
clofed by its ground cryftal (topper. As tho
muriatic acid can only fubiift in the galTcous
form, in the ordinary temperature, wc cannot
condenfe it without the prcfencc of water. Hence
the ufe of the water with which the bottles in
Woulfe's apparatus are half filled ; the muriatic
acid gas, driven off from the fea-falt in the retort,
combines with the water, and forms what the old
chtmiiis called Jittoakinjf/pirii of fait ^ or Glauber's

fpirit of fca-faU^ which wc now name muriatic
acid.

The ^d obtained by the above procefs is
ftill capable of combining with a further quantity
of oxygen, by being diftilled from the oxyds of
manganefe, lead or mercury ; and the refultinor
acid, which we name oxygenated muriatic

U

3o6

ELEMENtS

can only. like the former, exift in the gaffeous
form, and is abforbed, but in a much finaller
quantity, by water. When the impregnatioa
of water with this gas is pufhed beyond a cer-
tain point, the fuperabundant acid precipitates,
to the bottom of the veifels in a concrete form.
Mr Beithollet has fhown that this acid is capa-
ble of combining with a great number of the
falifiable bafes. The neutral falts which refult
from this union are fufceptible of deflagrating
with .charcoal, and with many of the metallic
fubdances ; but thefe delQ^grations are very vio-
lent and dangerous, owing to the great quantity
of caloric which the oxygen carries along with
it into the compofition of oxygenated ipuriatic
gcid *.

OF CHEIAISTRT.

307

Table oftbe Combinations qf Nitro-tnuriatic Acid
V)itb tbe Salifiable Safes, in tbe Order of Af-
Jinityj fo far as is known.

Names oftbe Bafes.

Names of tbe Neutral Salts:

Argill

Nitro-muriat of argilL

Ammoniac

ammoniac.

Oxydof

antimQn^

antimony.

filvcr ^

filvcr.

arfedic

arfenic.

Barjrtes

barytes.

Oxy4 of

bifmutb

bifmoth*

liime

lime.

Oxyd of

cobalt

opbalt*

copper

copper.

tin

tin.

iroi^

iron.

Magncfia

magnefia.

Oxyd of

manganefe

9ianganefe.

mercury

mercury.

molybdena

molybdena.

nickel

nickel.

gol4

gold.

platina

platina.

lead

lead.

Potaih

potaih.

Soda

foda.

Oxyd of

tungftein

tungftein.

zinc

zinc.

Ua

Sect.

J^o/r.— Mod of thefe combinations, efpecially thofc
with the earths and alkalies, have been little e:(amined,
and we are yet to learn whether they form a tp*
in which the compound radical remains combir
two acids feparate, to form two diftinft ncQtrd

3o8

ELEMENTS

Sect. XIX. — Obferuathns upon the Nttro-Muri-.
* atic * Acid, and its Combinations.

The nitro-muriatic acid, formerly caled aqua
re^ia, is formed bj a mixture of nitric and mu-
riatic acids. The radicals of thefe two atiids
combine together, and form a compound bafe,
from which an acid is produced, having proper-
ties peculiar to itfelf, and diflinifl ^rom thofe of
all other acids, cfpecially the power of diffolving
gold and platina.

In difTolutionsof metals in this acid, as in all
other acids, the metals are firft oxydated by at-
trading a part of the oxygen from the compound
radical. This occasions a difengagement of a

ot cAeSiistry.

i09

i

upon platina, in which I diflplved a eonfider^ble
quantity of that metal in nitro-muriatic acid.

I at firft fufpefted that^ in the mixture of ni-
tric and muriatic acids, the latter attracted a
part of the oxygen from the former, and be-
came converted into oxygenated muriatic acid,
which gave it the property of diflblving gold ;
but feveral &dts remain inexplicable upon this
fuppofition. Were it fd, we ihould be able to
difengage nitrous gas by heating this acid, which
however does not fenfibly happen. From thefe
confiderations, I am led to adopt the opinion
of Mr BerthoUet, and to confider nitro-muria-
tic acid as a fingle acid, with a compound bafe
or radical.

U3

Table

Sto

ELEMENTS

Tabl£ of tbe Combinations of Fluoric Acid witi^
the Salifiable Bafei, in tbe Order of Affiniiy.

Names of tbt Baftt.

liama of tbt Neutral Saki.

Lime

iluat of lime *

Barytes

barytes.

Strontites

ftrontitfs.

Magnelia

magnefia.

Potafti

potadi.

Sorta

foda.

Ammoniac

ammooiac.

Oxyd of

zinc

line.

manganefe

manganefe*

iron

iron.

lead

lead.

I .

OF CHEMISTRY. 3U

Sect, XX. — Obferontions upon the Fluoric Add^

and its Combinations.

Fluoric acid exiits ready formed ty Nature,
in the fluoric fpars "*, combined with calcareous
earth, fo as to form an ipfoluble neutral fal^t.
To obtain it, difengaged from that combination,
iluor fpar, or fluat of lime, is put into a leaden
retort, with a proper quantity of fulphuric acid ;
a recipient, likewife of lead, half full of water,
IS adapted, and fire is applied to the retort. The
fulphuric acid, from its greater affinity, expels
the fluoric acid, which pafles over and is abforb-
ed by the water in the receiver. As fluoric acid
is naturally in the gaflTeous form in the ordinary
temperature, we >can receive it in a pnuemato-
chemical apparatus over mercury. We are obli-
ged to employ metallic veflels in this procefs,
becaufe fluoric acid diflfolves glafs and flliceous
earth, and even renders thefe bodies volatile,
carrying them over with itfelf in diftillation in
the gafleous form.

We are indebted to Mr MargrafF for our firfl:
acquaintance with this acid ; though, as he could

U 4 never

* The beautiful fpars from Derby(hire are of this kind.
— T.

ZLZMEXTS

iree 6co ccsslHDatioa vidi ■
r;j.:-iir-iij: ri-irt:::?" c£ &I:cecu3 eaith, he wis
^:-:*n:r- re ?= Set^ x^ aciJ ibi ^coenK. The
Z'-i^ ;i t-^Lscrcrt. «ader thrnarac CI Mr Bott-
^;;:r:r. r^Ui ; .-.-iertbiT iacmied our knowledge
ic > rr-oerrx* ; ir>i Mr Scbeeie teems to hare
<3.i>. .:tri. ;js f^oil. Tbe oolv thing remaio-.
TK > '• sroTAiccr r> diictner the nature of
^ i:vrjc raiiciL of which we canoot hitherto
ianr. sr-* ?iru. « tfe xid coes cot appear to
M"!; ivf.t itfcum^'Ki in my experiment. It is
.Mi' J- rvjss ctcwBjooai affinity that cxperi-
TTc:?v .-cirtc t: V mAe with this Tiew, with

OF CHEMISTRY.

313

Table oftbe Combinatiotu afSorack Acid <mtb
the Salifiable Bafts, in tbc Order <if Aginit].

Bt/a.

Ntvtral&ibt.

Lime*

Borat of lime.

Barytes

barytes.

Strontitts

ftrontites.

Magnefia

magoeSa.

Potafli

potaOi.

Soda

foda.

Ammoniac

ammoniac.

Oxj-dof

lino

zinc.

iron

iron.

lead

lead.

tin

tin.

cobalt

cobalt.

copper

copper.

nickel

nickel.

mercury

mercury.

ArgiU

argill.

Sect.

Noit, — Moft of the&corobinations were nsither Icnoffat
oor named by tbc old cbemiQi. Tbe boracic acid was
formerly called fidative fait, aad ita compouiids iorv,
with bafe of fixed vegetable alkali, &c. — A.

* ByDr Hope's experiments, in his paper on Rronti-
tes, read to the Ki^ Society of Edinburgh, lime follows
karytes, an4:tIw7fii^mority between lime and ftrontites

jgfljWffirtB.— T.

ELEMENTS

?tvv. X\I. — Ohfervations upon Boracic ^cid^
and itj Combinations .

This is a concrete acid, extraded from a fait
procured in India, called borax or tincali. Al-
though borax has been very long employed in
the arts, we have as yet very imperfed know-
ledge of its origin, and of the methods by which
it is extraded and purified ; there is reafon to
believe it to be a native fait, found in the earth,
in certain parts of the eall, and in the water of
fome lakes. The whole trade of borax is in the
hands of the Dutch, who have been exclufively

OF CHEMISTRY. .315

fblphuric acid, or any 6t£ier having greater af^
Unity to foda than the boracic acid ; this latter
acid is feparated^ . and is procured in a cryftalline
form by cooling. This acid was long confider«
€d as being formed during the procefs by which
it is obtained^ and was confequently fuppofed
to differ according to the nature of the acid
employed in feparating it from the foda ; but
it is now univerfally acknowledged that it is
identically the fame acid, in whatever way pro^
cured, provided it be properly pyrified from
mixture of other acids, by waftiing, and by re-
peated folution and cryllallization. It is foluble
both in water and alkohol, and has the pro-
perty of communicating a green colour to the
flame of that fpirit. This circumftance led to
a fufpicion of its containing copper, which is
not confirmed by any decifive experiment : On
the contrary, if it contain any of that metal, it
mud only be confidered as an accidental mix-
ture. It combines with the falifiable bafes in
the humid way ; and though, in this manner, it
is incapable of diifolving any of the metals di-
reftly, this combination is readily afFeded by
compound affinity.

The Table prefents its combinations in the
order of affinity in the humid way ; but there
is a confiderable change in the order, when
we operate via ficca j for, in that cafe, argil!,

though

^i6 ELEMENTS

though the laft in our lift, muft be placed im-
mediately after foda.

The boracic radical is hitherto unknown, no
experiments having as yet been able to decom-
pofe the acid ; but we conclude, from analog]!^
with the other acids, that oxygen exifta in its
compofition, as the acidifying principle.

TABtB

OF CHEMISTRT.

317

Table of tb^ Combinations ofArfiniae yicidwitb
tbe Salifiable Safes, in tbe Order <ff Affinity.

Ba/a.

Niutral Salts.

Lime

Arfeniat of lime.

iSatytes
3trontite9

barytes.
ftrontites*

Magnefia

Potaih

Soda

magnefia. ^

potaih.

foda.

Ammoniac

ammoniac,

pxyd of

zinc

7.inc.

manganese

inanganefc.

iron

iron.

lead

lead.

tin

tin.

cobalt

cob^t.

copper
nickel

copper.
nickeL

bifmuth

bifmuth.

mercury

mereury.

antimony
filver

antimony,
filver.

gold
platina
Argill

gold.

platina.

argilL

Sect

iVIo/^.T— This order of falts was entirely unknown to the
pld chemifis. MrMacquer, in 1746, difcovered the com-
binations of arfeniac acid with potaih and foda, to which
^ gave ihe naiue oi arfenical neutral faits^'-^A,

3i8

ELEMENTS

Sect. XXII. — ObfiroatioTU »poa Arfeniac Acid,
and its Combinations.

In the CoUedions of the Academy for 1746,
Mr Macquer flieWs, that when a mixture of
white oxyd of arfenic and nitre are fubjeded to
the action of a Urong fire, a neutral fait is ob-
tained, which he calls neutral fait of arfenic.
At that time, the caufe of this fingular pheno-
menon, in which a metal a£ts the part of an a-
cid, was quite unknown ; but more modern
experiments teach, that, during this procefs,
the arfenic becomes oxygenated, by carrying
off the oxygen of the nitric acid ; it is thus
converted into a real acid, and combipes with

OF CHEMISTRY. 319

may be coUeded in proper veflels. The ar-*
fsniao acid is entirely freed from the other acids
employed during the procefs by heating it in a
crucible till it begins to grow red ; what remains
is pure concrete arfeniac acid.

Mr Scheele's procefs, which was repeated
with great fuccefs by Mr Morveau, in the la-
boratory at Dijon, is as follows : Diftil muria-
tic acid from the black oxyd of manganefe;
this converts it into oxygenated muriatic acid,
by carrying oflf the oxygen from the manganefe ;
receive this oxygenated acid in a recipient, con-
taining white oxyd of arfenic, covered by a little
diftilled water ; the arfenic decompofes the oxy-
genated muriatic acid, by carrying off its fuper-
faturation of oxygen, and is converted into arfe-
niac acid, while the oxygenated muriatic acid
is brought back to the Hate of common muriatiq
acid. The two acids are feparated by diftilla-
tion, with a gentle beat increafed towards th^
end of the operation ; the muriatic acid pafles
over, and the arfeniac ^cid remains behind in 4
white concrete form.

The arfeniac acid is confiderably lefs volatile
than white oxyd of arfenic ; it often contains
white oi^yd of arfenic in folution, owing to its
not being fufficiently oxygenated ; this is pre--
vented by continuing to add nitrous acid, as
in the former procefs, till no more nitrous gas
|s produced. From all thefe obfervations, I

would

'I

310 ELEMENTS

would give the following definition of arfenJAC
scid. It is a white concrete metallic acid, form-
ed by the combination of arfenic with oxygen ;
it is fixed in a red heat, is foluble in water, and
U capable of combining with many of the fali-
iiable bafes.

Sect. XXII l.-~-Ob/frvationr upon Molybdic Acid,
and its Combinatietu with Acidijiabie Bafes *.

Molybdena is a particular metallic body, ca-
pable of being oxygenated, fo far as to become
a true concrete acid f . For this purpofe, one
part by weight of the ore of molybdena, which
is a nutiinil fiilphuret of that metal, is put into
a retort, with five or fix parts of nitric acid, di-

Of CtiUlVtlStRt. 32i

df nitrous gas efcape ; the molybdena is then
oxygenated as far as is poffible, and is found at
the bottom of the retort in a pulverulent form,
refembling chalL It mud be wafhed in warm
water, to feparate any adhering particles of fuL
phuric acid ; and, as it is hardly foluble, we lof<(
Very litle of it in this operation. All its combi-
nations with falifiable bafes were unknown to
the old chemifts *i

Table

* Meffra ToQdi and Ruprecht h;k^e lately reduced Mo-'
jybdena to the reguline date, by a fimilar procefs to that
formerly defcribed for reducing the metals of Chalk, Mag-
neiia and Barytes. They defcribe the metallic button as
being convex and compa^V, and refembling fleel in its co-
lour i its fracture is uneven and grannlated, and has more
metallic luftre internally than on the furface ; it is brittle^
not hardy and not attradible by^the magnet. On the
furface of one of the buttons procured in thefe experi-
ments fome little cavities were obferved, in which the
motal had crjflallized in form of prifmatic needles,
which were too fmall to allow of their particular configu-
ration being accurately determined. The fpecific gravity
of this metal, according to the experiments of Mr Haid-
inger, counfellor of the Schemnitz mines, is 6.963, watei*
taken as x.ooo.«-T.

X

ELEMENTS

Table q/" tbe Combinatioaj of Tungftic Acidvutb
Ibe Salifiable Sq/ii.

Bafa.

I^tutral SaUs.

Lime

Tungftat of lime.

Barytes

barytes.

Magnefia

magneiia.

Potaflx

potafh.

Soda

foda.

Ammoniac

ammoniac.

Argill

argill.

Oxyd of

antimony *,

, &c. antimony f , &c.

of CHEMISTRT. ^ 323

froiri a pearl-white to a yellow and reddifh ; it
is found in feveral parts o( Saxony AM Bohe^
mia.- The mineiral balled Wolfram, which is fre-
quent in the mines of Cornwall, is likewife an
ore of this metal, in all thefe ores the metal is
oxy dated ;' and, in foiOT of them, it appears
even to be oxygenated to the ftafe of acid, being
combined with lime* into a true tungftait of lime;
To obtaiti tbe acid free, mix one part of ore 6f
tungileib wita four parts of carbonat of potafli^
and melt the rriixture in a crucible ; then powder
it and pour on twelve parts of boiling Ivater, add
nitric aci^,' arid the tungftic acid precipitates iri
a concrete form. Afterwards, to infure the coiti-
plete oxygenation of the metal, add more ftitric
acid,, and evaporate to drynefs, repeating this
operation To long as red fumes of nitrous gas are
produced. To procure tungftic acid perfedtly
pure, the fufion of the ore with carbonat of pot-
aih mufl be made in a crucible of platina, other-
wife the earth of the common crucibles wilt niix
with the prod uds^ and adulterate the acid.

Xa ;.,T^BLE

* ** . I

' '•^

H 334 ELEMENTS 1

H Table of the Combtnations of Tartarous jicid with |

K- the Salifiable Bafts

, in the Order of Affinity.

^^^Z Bafii.

Neutral Sail!.

^^^^^V Lime

Tigrtarite of lime.

^^^^B Barytes

barytes.

^^^^^B

ilrontites.

^^^^1 Magnefia

magnefia.

^^^H FotaOi

potafii.

^^^ Soda

foda.

^^P^^ Ammoniao

ammoniac.

■ ArgtU

argill.

^K Oxyd of

^H

zinc.

^K

iron.

^^^B manganefe

mangaoele.

^^^^H

cobalt.

^^P^^ nickel

nickel.

■^ lead

kad.

H

tin.

^B, copfKr

copper.

H blfinuth

bifmuth.

^H antimony

antimony. ^^

^H arfenic.

arfenic. ^^^|

H filver

tI

^H mercury

mercury.

^B gold

gold.

^^^^^^ pistina

platina.

^k

Sect.

H.

OF CHEMISTRY. 325

Sect. XXV. — ObferoaHons upon Tartarous A*^

ctdj and its Ctmbinaiions.

Tartar, or the concretion which fixes to the
infide of veflels in . which the fermentation of
wine is completed, is a well known fait, com-
pofed of a peculiat acid, united, in confiderable
excels, to potaih. Mr Scheele firft pointed out
the method of obtaining this acid pure: Ha-
ving obferved that it has a greater affinity to
lime than to potafli, he direds us to proceed in
the following nmnner. Diflblve purified tartar
in boiling water, and add a fufficient quantity
of lime till the acid be completely faturated.
The tartarite of lime, which is thus formed, be-
ing almoft infoluble ip cold water, falls to the
bottom, and is Separated from the folution of
potaih by decantatioa; it is afterwards, waihed
in cold water, and *dried ; then fome fulpburia
acid, diluted with eight: or nine parts of water^
is poured on ; digeil for twelve hours in a gentle
heat, frequently ftirring the mixture, and the
fulphuric acid combines with the Uipe, leaving
the t;artarous acid free. A fmall quantity of
gaSy not hitherto examined, is difengaged during
this procefs. At the end of twelve hours, ha-
ving decanted off the clear liquor, waih the ful-
phat of lime in cold water, which add to the
decanted liquor, then evaporate the whole, and

X3 the

3=6

ELEMENTS

tbe tartarous acid is obtained in a concrete foim.
Two pounds of purified tartar, b^ means o^^fl
from eight to ten ounces of fulphuric acid, yiel4 ^ r
about eleven ounces of tartarous acid.

As the combuftible radical exills in excefs, or •
as the acid fiom tartar is not fully i'aturated.
with oxygen, we call it tartarous acid, and tho'
neutral falls, formed by its combinations withi
faliftable bafes, are named tartaritei. The ba£fe>
of the tartarous acid is a carbono-hydrous or hy-J
dro-carbonous radical, lefs oxygenated than ia
the oxalic acid ; and it would appear, from thel
experiments of Mr Haflenfrati, that azot enter*'
j;iio the compolUioii of the tartarous radical,
even in coniiderable quantity. By oxygenating-
tartarous acid ftill farther, it is convertible inta'*
oxalic, malic, and acetous acids ; but it is pro-^
bable the proportions of hydrogen and carbon inJ
the rudical are changed during thefe converiions,
and that the difterence between thefe acids does
not alone coniift in the different degrees of oxy-
genation.

The tartarous acid is fufceptible of two de-
grees of faturalion in its combinations with the
fixed alkalies ; by one of thefe a fait is formed
with excefs of acid, improperly called cream of
tartar, which in our new nomenclature is na-
med acuhihui tartartte of potajb ; by a fecond
or reciprocal degree of faturation a perfeiflly
neutral fait is formed, foruii-rly called vegetable

OF CHEMISTRY. 327

faU^ which we name tartarite ofpotajh. With
foda this acid forms tartarite of foda, formerly
calledya/ de Seignettey ox fal polycbrejl ofRochell^.

Sect^ XXVI, — Obfervations upon Malic Acid^
and its Combinations with tbe Salifiable Bafes f .

The malic acid exifts ready formed in the
four juice of ripe and unripe apples, and many
other fruits, and is obtained as follows : Satu-
rate the juice of appjes with potafh or foda, and
add a proper proportion of acetite of lead dif-
folved in water ; a double decompofition takes
place, the malic acid combines with the oxyd
of lead and precipitates, being almoft infoluble,
and the acetite of potaQi pr (bda remains in the
liquor. The malat of lead being feparated by
4ecantation, is waflaed with cold winter, and fome
dilute fulphuric acid is added ; this unites with
the lead into an infoluble fulphat, and the ma-
lic acid remains free in the liquor,

X 4 This

* This account of the poxppoiition of Rochell iaJt is nof
quite accurate : It is a triple fait, confiding of tartarous a-
ci4 faturated by foda and potafh, and is formed by comr
pletely neutralizing acidulous tartarite of potafh, by the
addition of a fuiEcieot quantity of foda.-~T.

+ I have omitted the Table, as the order of affinity 19
unknown, and is given by Mr Lavoifier only in alphabeti-
cal order. All the combinations of malic acid with fali-
'HUc bafes, which lure named malats^ were unknown t^

3*8

ELEMENTS

This acid, which is found mixed with citric
and tartarous acid in a great number of fruitSf
is a kind of medium between the oxalic and ace-
tous acids, being more oxjgenated than the for-
mer, and lefs fo than the latter. From this cir-
cumftancc, Mr Hermbftadt calls it imperfeSt vine-
gar ; but it differs likcwife from acetous add, bj
having rather more carbon, and lefs hydrogen,
in the compofition of its radical.

When an acid much diluted has been ufed in
the foregoing procefs, the liquor contains oxalic
as well as malic acid, and probably a little tar-
tarous; tliefe are feparated by mixing lime-wa-
ter with the acids, oxalat, tartarite, and malat
of lime :irc produced j the two former, being in-
fohible, are precipitated, and the malat of lime

OF CHEMISTRY.

3*9

Table of the Combinations of Citric Acid with
the Salifiable Bafes, in tbe Order of Affinity*.

Bafis.

Neutral Salts.

Barjtes

Citrat of barytC9« .

Lime

lime.

Magnefia

magnefia.

Potafh

potaih.

Soda

foda.

Amxnoiiiac

ammoniac

Oxyd of

zinc

zinc.

inanganefe

manganefe.

iron

iron.

lead

lead. .

cobalt

cobalt.

copper

copper.

arfenic

arfenic.

mercury

mercury.

antimony

antimony.

filver

filver.

gold

gold.

platina

platina.

Argill

argill.

Sect.

• Thefe combinations were tinknown to the old che-
snifis. The order of affinity of the falifiable bafes with
this acid was determined by Mr Bergman , and by Mr de
Qcenej of the Dijon Academy,— A.

ii3»

ELEMENTS

SiECT. XXVII. — Obfirvations upon Citric Ad^^
and its Combinations.

The citric acid is procured by expreflion from
lemons, and is found in the juices of many other
fruits mixed with malic acid. To obtain it pure
and concentrated, it is firll allowed to depurate
from the mucous part of the fruit, by long reft
ill a cool cellar, and is afterwards concentrated
by expoling it to the temperature of from 21''
to 23" of Fahrenheit ; the water is thereby fro-
zen, and the acid remains liquid, reduced to
about an eighth part of its original bulk. A
lower degree of cold would occafion the acid
to be engaged among the ice, and render it dif-
ficultly feparable. Thisprocefs was pointed out
by Mr Georgius.

It is more eaCly obtained by faturating the
lemon-juice with lime, fo as to form a citrat of
lime, which is infoluble in water ; wafli this fait,
and pour on a proper quantity of fulphuric acid ;
this forms a fulphat of lime, which precipitates
and leaves the citric acid free in the liquor.

OF CHEMISTRT.

331

Table of the Combinations of Pyro^Ugnous A-

cid with tbe

Salifiable Baffs, it^tbe Order of

Affinity *.

• • • . . *
■

Bafes.

Niutral ialtu

Lime

Pyro-lignite of lime,

Barytcs

barytcs.

Potafli

potafh.

§.od^

• foda.

* • •

Magnefia

magnefia.

Ammoniac

t ■ ammoniac ..

. Dxyd of

^IDC

zinc.

manganefe

manganefe.

iron

iron.

lead

lead*

tin

tin.

cobalt

cobalt.

•

copper

copper. ;

nickel

nickel.

arfenic

arfekuc.

bifmuth

. ^bifmuth.

mercury

ipercury. .

antimony

antimony.

filver

filver.

gold

gold.

platina

platina.

ArgiU

argill.

Sfict.

* The above affinities were determined by Meffrs de
Morveau and Eloi Bourfier de Clervauz. Thefe combi-
Ditions were entirely unknown till lately.— A.

ELEMENTS

z:t. XSyiU—Oifin^iau upon the Ffrol^.
Kims Acidy and its CowMaatieiu.

Tbe dd chemifts obforrd that moft of the
wxaU. efperiallv the more heavy and compaft
oncH give oat a particular add fpirit, bj dif-
tiiUtion in a naied fire ; bat, before Mr Goet-
lisg. who gives an account of his experiments
upon tbis I'ubjed in Ccdl's Chemical Journal for
X779, r.o one had ever made anj inquiry into its
nature and properties. This acid appears to be
the fame, whatever be the wood it is procured
from. When firft diftilled, it is of a brown co-
lour, and confiderably impregnated with carbon
and oil ; it is pnrified from thefe by a fecond

OF CHEMISTRY. 333

fbd acidulous tartarite of potalh, by diflillation
in a naked fire. To obtain it^ let a retort be
half-filled with powdered tartar, adapt a tubu-^
lated recipient, having a bent tube commtinica*
ting with a bell-glafs ' in a pneumato-chemioal
apparatus ; by gradually raifing the fire under
the retort^ we obtain the pyro-tartarous acid mix*
ed with oil, which ^ is ieparated by means of a
funnel. A vaft quantity of carbonic acid gas is
difengaged during the diflillation. The acid
obtained by die above procefs is much contami-
nated with oil, which ought to be feparated from
it. Some authors advife to do this by a fecond
diflillation ; but the Dijon academicians inform
us, that this is attended with great danger, from
cxplofions which take place during the procefs.

Table

rity to pyro-lignous acid, foppofes the order to be the
fame ia both ; but, as this is not afcertained by experi-
ment, the table is omitted. All thefe combinations, call-
ed Pyro-tartariieSf were unknown till lately.— T.

H^BHH^^^I

to

J

^^^334 ^H

^M Table of the Combinations of PyrD~mucous Acid |

^P "wUb tbe Salifiable Safes, t

H /*f Order of Jffi-

■

K Bafis.

Ntutral Salts.

^H > Potafh Pyro<mucite of potaHi. |

^B Soda

foda.

^V BarTtes

barytes.

^^L Lime

lime. .

^^^^H Magnefia

magnefia.

^^^^^V Ammoniac

ammoniac.

^^ Arglll

argill.

H^ Oxjd of

^^t

line.

^V manganefe

manganefe. ^^^fl

^H

^^^1

^B lead

lead. ^B

■

tin.

^H cobalt

cobalt.

^^1 cupper

copper.

^^P nickel

nickel.

^H arfenic

atfenic. .^^^

Hr birmutli

bifmuth. I^^^l

^K antimony

antimony. ^^^H

1

Sect.

^H * All ihcfe combinatkons were

unknown to the old

^H chetnilb. — A.

1.

m

^^^^^^^I^^^^^H

OF CHEMISTRY. 333

Sect. XXJIL'^Obfervations upon Pyro-muams
Acid^ and its Combinations.

This acid is obtained by diftillation in a naked
fire from fugar, and all the faccharine bodies ;
and, as thefe fubftances fwell greatly in the
fire, it is neceflary to leave feven-eights of the
retort empty. It is of a yellow colour, verging
to red, and leaves ^ mark upon the fkin, which
will not remove but along with the epidermis.
It may be procured lefs coloured, by means of
a fecond diftillation, and is concentrated by
freezing, as is directed for the citric acid., It is
chiefly compofed of water and oil, flightly oxy-
genated, and is convertible into oxalic and ma-
lic acids, by farther oxygenation with the nitric
acid.

It has been pretended that a large quantity of
gas is difengaged during the diftillation of this
acid, which is not the cafe if it be conduded
flowly, by means of moderate heat.

Table

^^■H

■

^^n

336 E L E M

^^^H

Table of the Combinations of the Oxalic Acid ^^^

with the Salifiable Safes

m the Order of4fiJ^^

nity '.*

Baft,.

NfiUrai Sa/ti. ^^1

Lime

Oxalat of lime. ^^|

Barytes

barytes. ^^|

Sti'onlites

ftrontites. ^^|

Magnefia

magnefia. . ^^H

Potafli

potafh, ^^H

Soda

^H

Ammoniac

ammoniac. ^^M

ArgiU

argilL ^^^H

Osyd of

^^^^H

xinc

^^^^^^H

iron

>i^^^^^|

manganele

manganefe. ^^|

cobalt

cobalt. ^H

nickel

nickel. ^^B

. lead

^M

copper

^H

bifinuth
1 antimony

bifmutb. ^^M
antimony. ^^H

arfenic

arfenic. ^^H

mercury

mercury. '^^f

filvcr

.^^^^1

gold

^I^^H

platina

■ AH unknowQ to

the old cbemiaa.— A. ^H

^^^^

^^^^^^^^f^^^^B

OF CHEMISTRY. 337

...■•■■' . . . »

Sect., XXXI. — Obfervations upon Oxalic Acidf

and iu Combinations.

The oxalic acid is moftly prepared in Switzer-
land and Germany from the expreffed juice of
forrel, from which . it cryftallizes by being left
long at reft ; in this ftkte it is partly faturated
with potafli,. forming a true acidulous oxalat of
potaQi, or fait with exccfs of acid. To obtain
it pure, it muft be formed artificially by oxyge-
nating fugar, which feems t6 be the true oxalic
radical. Upon one part of fugar pour fix or
eight parts of nitric acid, and apply a gentle
heat; a confiderable effervefcerice takes place,
and a great quantity of nitrous gas is difenga-
ged ; the nitric acid is decompofed, and its oxy-
gen unites to the fugar : by allqwing the liqupr,
to ftand at reft, cryftals of pure oxalic . acid are
formed, which muft be dried upon blotting pa-i
per, to feparate any remaining portions of nitric
acid ; and, to enfure the purity of the acid, dif-
folve the cryftals in diftUled water, aod cryftaK
lize them afrefti.

From the liquor remaining after the firft cryf-
tallization of the oxalic acid we may obtain
malic acid by refrigeration : TVw.acid is more
oxygenated than the oxalic- 5-' aw3 by a further

. Y - '- (>^ygitiat!on.

338

ELEMENTS

oxygenation, the fugar is convertible into i
toua acid, or vinegar.

The oxalic acid, combined with a iinall qO
tity of foda or potafh, has the property, '
tartarous acid, of entering into a number of
binations without fuffering decompofition : 1
combinations form triple falls, or neutral (
with double bafes, which ought to have proper
names. The fait of forrel, which is potafti ha-
ving oxalic acid combined in excefs, is named
acidulous oxalat of potafli, in our new nomen-
clature.

The acid procured from forrel has been known
to chemiUs for more than a century,, being men-
tioned by Mr Duclos in the Memoirs of the A-
cademy for 1688, and was pretty accurately de-
fcribedby Boerhaave; butMrScbeelefirftniewed
that it contained potalh, and demonftrated its
identity with the acid formed by the oxygena-
tion of fugai.

Sect. XXXII. — Obfervations upon Acetous Acid,
and its Combinations.

This acid is compofed of carbon and hydro-
gen united together, and brought to the ftate
of an acid by the addition of oxygen ; it is con-
fequently formed of the fame elements with
the tartarous, oxalic, citric, and malic acids, and
others,

• . I . .

I

A

I ♦

..^

•%t 14 • • • • '

. \

t ■ • i 1

. /•■

P

{

• ■ I

• » . ■ I

J • VI

. I . . . . /

> . •■ J I 1

* 1 f

• I'

\

OF CHEMISTRY. 339

Others, but the elements cxift in different pro-
portions in each of thefe ; and it would appear
that the acetous acid is in a higher Hate of oxy^
genation than thefe other acids. I have fome
reafon to believe that the acetous radical con-
tains a fmall portion of azot ; and as this ele-
ment is not contained in the radicals of any ve-
getable acid, except the tartarous, this circum-
ilance is one of the caufes of difference; The a-
cetous acid, or vinegar, is produced by expofing
•wine to a gentle heat, with the addition of fome
ferment 1 This is ufually the ley, or nlother,
which has feparated from other vinegar during
fermentation, or fome fimilar matter. The fpi-
rituous part of the wine, which confifts of car-
bon and hydrogen, is oxygenated, and convert-
ed into vinegar : This operation can only take
place with free accefs of air, and is always at-
tended by a diminution of the air employed, in
Confequence of the abforption of oxygen ;
wherefore it ought always to be carried on in
veflTels only half filled with the vinous liquor
fubmitted to the acetous fermentation.

The acid formed during this procefs is very
volatile ; it is mixed with a large proportion of
water, and with many foreign fubftances, and
to obtain it pure, it mud be diftilled, in (lone or
glafs veflels, by a gentle fire« The acid which
pafles over in diftiUation is ibme«r|nt changed

by the procds^ w fiwne

ire

:ao

ELEMENTS

niiture with what remains in the alembic, but
feems lefs oxygenated : This ciicumftance has
not been formerly obfcrved by cheraills.

Diilillatton is not fufficient for depriving this
acid of all its unneceflary water ; and, for this
purpofe, the heft way is by expofing it to a degree
of cold of from ig' to 23" of Fahrenheit ; by this ,
means tlie aqueous part becomes ffozen, and
leaves the acid in a liquid ftate, and confider^*
biy concentrated. In the ufual temperature, of
the air, this actd can only esill in the gafleous
form, and can only be retained by combination
M'ith a large proportion of water. There are
uther chemical procefies for obtaining the ace-
tous acid, which conlift in oxygenating the tar-
tarous, oxalic, or malic acids, by means of nitric

OF CHEMJSTRY.

341

whh refpeA to folability, and the malic acid is
in the middle degree of faturation between the
oxalic and acetous acids. With this. 8S with all
the acids, the metals require to be oxydated pre-
vious to folution.

The older chemifts 'knew hardly any of the
falts formed by the combinations of acetous acid
with the falifiable bafes, except the acetites of
pota(h, foda, ammoniac, copper, aiid lead. Mr
Cadet difcovered the acetite of arfenjc * ; Mr
Wenzel, and the Bijon academicians, Mr de Laf-
fone and Mr Proull, made us acquainted with
the properties of the other acetites. From the
property which acetite of potaQi poffefles, of gi-
ving out ammoniac in dtftillation, there is fonie
reafon to fuppofe, that belides carbon and hydro-
gen, the acetous radical contains a fmall propor-
tion of azot ; though it is not impoffible but the
above production of ammoniac may be occafiori-
e4 by the decompofttion of the potalh.

Y3

Table

• gayans Etiangcrs, Vol. Ill,

ELEMENTS

Table d/ the Combinations of Acetic Acid with
the Salifiable Bajes, in tbe Order of Affimtj.

Bafoi.
Barvtes
Fotalh
Soda
Lime
Magnefia
Ammoniac
Oxyd of

line

manganefe

iron

lead

tin

cobalt

Neutral SaUi.
Acetat of barytes.
potafti.
foda.
lime.
magnefia.
ammoniac.

^inc.

manganefe,

iron.

lead.

tin.

cobalt.

OF CHEMISTRY.

Sect. XXXIII. — Obfervatiotis apart Acetic Add,
and its Combinations.

We have given to radical vinegar the name of
acetic acid, from fnppofiBg that it conflfts of the
fame radical with that of the acetous acid, but
more highly faturated with oxygen. According
to this idea, acetic acid is the' higheft degree of
oxygeii.atioo of which the hydro-carbonous radi-
cal is fufceptihle ; but although this circum-
ftance be extremely probable, it requires to be
confirmed by farther and more decifive experi-
ments, before it be adopted (as an abfolute che-
mical truth. We procure this acid as follows :
Upon three parts acetite of potafli or of copper,
pour one part of concentrated fulphuric acid,
and, by diftillation, a very highly concentrated
vinegar is obtained, which we call acetic acid,
formerly named radical vinegar. It is not hi-
therto rigoroufly proved that this acid is more
highly oxygenated than the acetous acid, nor
that the difference between them may not con-
fill in a different proportion between the ele-
ments -oi the radical or bafe.

T4

Tabx-k

^^^^^^BIH

B 3^4 ELEMENTS ^^M

H TxiXt of the Combintuiofu <f Succinic Acid CBlfj^^J

■ tbc Salijiablt BaJUt

in the Order ofAffimtj^^^

^^B - ^«■^-

NtutralSah,. ^^^

^^^^B £arytes Succinat of barytes. |

^^^^B

lime.

^^^^1

potaHi.

^^^B

foda.

^^^^^ Ammoniac

ammoniac

V Magnefu

magnelia.

■ , ArgiU

■ ' Oxydof

argiU.

^^' xinc

zinc.

^^^^H .

iron. ^_

^^^^^B maaganeic

manganefe. ^^H

^^^^K",

cobalt. ^^^1

^^^K' '

^^H

^V^^ :W

m

^^^^* ■

tin. ^^B

^f copper

copper. 1

^B bifmutb

biimuth. 1

^H sDtimonj

antimony. 1

^K arfenic

adeaic. 1

^V mercury

mercury. ,^^J

H Qlver

^H

■ gold

^H

^m platina

platina.

SiCT.

^^^^ ifbte. — AU the fuccinats

were unknown to ihc (dder

^^^^^ chenuQa. — A.

^M

Sect. XXXIV.^^Obfervations upon Succinic A^
, cid^ and ifs CambinMions.

Tbp fuccinic acid is drawn from amber by
fublimation in a gentle heat, and rifes in a con-
crete form into the neck of the fubliming vefleL
The operation muft not be puihed too far, or hy
too ftrong a fircy otherwife the oil of the amber
rifes alpng with the acid. The fait is dried up<P.
on blotting p^per, and purified by repeated fo«
lution and cryftallixation. »

The acid is foluble in twenty-four times its
weight of cold water, and in a much fmaller
quantity of hot water. It poflefles the qualities
of an acid in a very fmall degree, and only af-
fedls the blue vegetable colours very flightly.
The affinities of this acid, with the falifiable
bafes, are taken from Mr de Morveau, who h
the firit chemift that has endeavoured to afcec^
tain them, ->

Sect.

346

ELEMENTS

Sect. XXXV. — Obfirvations upon Benzoic Acid,
and its Combinatioiu with SaUfiable Bafei *.

This acid was known to the ancient chetnifts
under the name of the Flowers of Benjamin, or
of Benzoin, and was procured by fublimation,
from the gum or relin called Benzoin : The
means of procuring it, vto bumida, was difco-
yered by Mr Geoffrey, and perfefted by Mr
Scheele. Upon benzoin, reduced to powder,
pour flrong lime-water, having rather an excefs
of lime -J keep the mixture continually ftirring,
and, after half an hour's digeftion, pour off the

OF CHEMISTRY. 347

diflblTsd, while the benzoic acid, being info-
luble, precipitates in a concrete form.

Sect. XXXVI. — Obferaationt upon Camfbarie
Acidy and its Combinations witb Salifiable
Ba/es*,

Camphor is a concrete eflential oil, obtained,
by fublimation, from a fpecies of laurus which
grows in China and Japan. By diftilling nitric
acid eight times from camphor, Mr Kofegarten
converted it into an acid analogous to the oxa-
lic ; but, as it differs from that acid in fome
circumftances, we have thought neceflary to give
it a particular name, till its nature be more com-
pletely afcertain?d by farther experiment.

As camphor it a carbono-hydrous or hydro-
carbonous radical, it is eaiily conceived, that,
by oxygenation, it Ihpuld form oxalic, malic,
and feverai other vegetable acids : This conjec-
ture is rendered not improbable by the experi-
ments of Mr Kofegarten; and the principal
phenomena exhibited in the combinations of
(lamphoiic acid with the falifiable hafes, being
very

* Thelf conobliiBtions, which were all anknown to the
tAd cbtmiRs, are called Camphorata. The table is omit-
ted as being only in alphabetical order. — T,

}4» ELEMENTS

Terj fimilar to thofe of the oxalic and malic a-
cids, lead me to believe that it coofifU of a miz-
ture of thefe two acids.

Sect. XXXV It— Ob/erva$hiu upon GaBu Acid^
and its Combinations with Salifiable Bafcs*.

The Gallic acid, formerly called the Principle
of Aftringcncy, is obtained from gall-nuts, either
by infufion or decodion with water, or by dif-
tiltation ^'ith a very gentle heat. This acid
has only been attended to within thefe few
years. The committee of the Dijon Academy
have followed it through all its combinations,
nd give the beft account of it hitherto produ

Ol' CHEMiSTHY. S4$i

#

in oak, willow, marfh irisi, the iirawbcrry^ v^m^
phea, Peruvian bai4c, the floirers and bark o£
pomegranate^ and in manjr other woods and
barks.

cidy and its Combinations with Salifiable Bafes ^*

The only accurate knowledge we have of this
acid is from the works of Mr Scheele. It is
contained in whey, united to a fmall quantity
of earth, and is obtained as follows : Reduce
whey to one eighth part of its bulk by evapo-
ration, and filtrate, to feparate all its cheefy
matter •, then add as much lime as is neceffary
to combine with the acid ; the lime is afterwards
difengaged by the addition of oxalic acid, which
Combines with it into an infoluble neutral fait.
When the oxalat of lime has been feparated by
decantation, evaporate the remaining liquor to
the confidence of honey ; the ladic acid is dif-
folved by alkohol, which does not unite with
the fugar of milk and other foreign matters;

thefc

* Thefe combinations are called LaSats ; they were all
UDkaowd to the older chemifis, and their affinities have
not yet bceb idSantttned.--*- A.

350

ELEMENTS

the&are feparatcd by filtration from the alko-
hol and acid ; and the alkohol being evapora-
ted or diftilled off, leaves the laftic acid be-
hind.

This acid unites with -" the falifiable bafes,
forming falts which do not cryftallize ; and it
feems confiderably to ref ible the acetous a-
cid.

OF CHEMI8TBLT.

3S«

Table 9f the Combiaationt iif SaccbO'laSic
vuitb the Salifiable Sa/et, in the Order ((fAffi-
nitj.

Safes.

Niwiral Saku

Lime

Sac^olat of lime.

•

Barytes

barytes.

Magnefia

magnefia.

Potaih

. potaflu

Spdsi

foda.

Animoniac

ammoniac.

ArgiU

argilL

Oxyd of

zinc

zinc.

nianganefe

manganefc.

iron

iron.

lead

•

lead.

tin

tin.

cobalt

cobalt.

copper

copper.

nickel

nickel.

arlenic

arfenic.

bifmuth

bifmuth.

mercury

mercury.

antimony

antimony.

filver

filver.

JWaltf.— AU thcfc were uxxknown to the older chemifb*
'^ 3

is^

ELEMENTS

Sect. XXKIX. — Obfcrvaiions upon SaccbO'laa
j^cid, and its Combinations.

A fpecies of fugar may be estrafled> by eva-
poration, from whey ; this fubftance has long
been known jn pharmacy, and has a confide-
rable refemblance to that procured from the
fu gar-cane. This faccharine matter, like or-
dinary fugar, may be oxygenated by means of
nitric acid : For this purpofe, feveral portions of
nitric acid are diftillcd from it ; the remaining
liquid is evaporated, and fet to cryflallize, by
which means cryftals of oxalic acid are procu-
red ; at the fame time a very fine white potv-a
der precipitates, which h the faccho-laflic acidf
difcovered by Scheele, It is fufccptibic of com-
bining with ail the alkalies, with the earths,
and even with the metals : Its action upon the
latter is hitherto but little known, except tbat,J
with tliem, it forms difllcultly folublc falts. f
The order of affinity in the table is taken froraJ
Bergman.

TablkI

OF CHEMISTRY.

353

Table of the Cmbinaiiotu t^ Formic Acid tvitb
the Salifiable Bafes, in the order of Affinity.

Bafit.

Neutral Sahi.

Barytes

Formiat of barytes.

Potafli

pota(h.

Soda

foda*

Lime

lime.

Magnefia

tnagnefia.

Ammoniac

ammoniac^

Oxyd of

ftinc

zinc.

muuganefe

manganefe.

iron

• iron.

lead

lead.

tin

tin.

cobalt

cobalt.

copper

copper*

nickel

nickel.

bifmuth

bifmuth*

filver

filver.

Argill

argill.

Sect*

^o/^.— All unknown to the older chemifls. — A.

354

ELEMENTS

Sect. X.L.—Ob/ervatioiu upan Formic Acid, and
Us Combinathnt.

This acid was firfl dbtained by diflillattoo
from ants, in the laft century, by Samuel Fifher.
The fubjed was treated of by Margraff in 1749,
and by MelTrs Ardwiflan and Ochrn of Lapfic
in 1777. The formic acid is extraded from a
large fpecies of red ants, formica rufa^ Um.
which form large ant hills in woody places. It
is procured, either by difUlling the ants with t
gentle heat in a gla& retort or an alembic ; or,
after having wafhed the ants in cold water, and
dried them upon a cloth, by pourii^ on boiling
water, which diflblves the acid ; or the acid may

OF CHEMISTRY. 355 -

Sect. XLI. — Obfervations vpon Bomhic Aciil,
and its Combinathnt wiib Acidifiable Bafei *■

Tbe juices of tfae lilk worm reem to afTume an
acid quality when that infed changes frdm the
larva to the chryfalis ftate. At the moment of
its efcape from the latter to the butterfly form,
it emits a i^ddirh Uguor, \vhich reddens blue pa-
per, ind which was firft attentively obferved by
Mr Chauffier of the Dijon Academy : He ob-
tained the acid by infufing filk-worm chryfalids
in alkohol, which diflblves their acid without
being charged with any of the gummy parts
oftheinfed; and, by evaporating the alkohol,
the acid remains tolerably pure. The proper-
ties and affinities of this acid are not hitherto
afcertained with any precifion ', and we have
reafon to believe that analogous acids may be
procured from other infecls. The radical of this
acid is probably, like that of the other acids from
the animal kingdom, compofed of carbon, hy-
drogen, and azot, with the addition, ^perhaps, of
phofphorus.

X 2 Table

" Thefe combuiuions, nsmed Bombats, w«re unknown

o the old diemifts ; and ihe atfiniiies of the falifijble baC^a
ibic add arc hithcno undetermined. — A.

35(i

ELEMENTS

Table of the Combinathns of the Sebacie Jidd
with the Salijiable Safes, in the Order of Affi-
ttitjt.

Bafa.

NtutralSatlu

Batytes

Sebat of barytes.

Potalh

potalh.

Soda

foda.

Lime

lime.

MagneGa

magaefia.

Ammoniac

ammoniac*

Argill

argilL

Ox>d of

OF CHEMISTRY. 357

Sect. XLlL^^Obfervations upon Sebacic Acid,

and its Combinations.

To obtain the febacic acid, let feme fuet be
melted in a ikillet over the fire, along with fome
quick-lime in fine powder, and conftantly ftir-
red, raifing the fire towards the end of the ope-
ration, and taking care to avoid the vapours,
which are very oflfenfive. By this procefs the
febacic acid unites with the lime into a febat of
lime, which is difficultly foluble in water ; it is,
however, feparated from the fetty matters with
which it is mixed by folution in a large quantity
of boiling water. From this the neutral fait is
feparated by evaporation ; and, to render it pure,
is calcined, re-dilTolved, and again cryftallized.
After this we pour on a proper quantity of ful-
phuric acid, and the febacic acid paifes over by
diflillation«

% 3 Sect,

.15»

ELEMENTS

>i. >. I . \ t .1 1 l.—Ob/ervathtu upon tbe UtbicAeid,
^H,hri l,\imhiHalions wilb tbe Salifiable Bq/et*.

Vwnx x\w later experiments of Bergman and
.'sluslt-, \\w uriiiftry calculus appears to be afpe-
. ). > .>t u\x \\ ith nn earth/ bafls ; it is flightly
a. ttUilous n»J n'qiiim a large quantity of wa-
tvx ^^^ u^l»lion, ihite gnini being fcarcely fo-
^t^u' ti> « iWulUhl {Alts nf boiling water, and
iJio ;■.lVs^-^ ^^at^ «j;«in cryftalUtes when cold. To
i>, X ,^^l^^v^o j»^'iJ» which Mr De Morveau calls
(W \ .l',: %:,.. M.- i;i\c the ».ur.e of Lithlc Acid,

or CHEMISTRY.

359

Table of the Combinationt nf tbc PruJIic Acid
mlb tbe Salifiable Bafii, in tbt Order of Affi.
nit}*.

Bafii.

tiettral Saki.

Fotafh

FrulBatjofpotalh.

Soda

foda.

AmmoDiac

ammoniac.

Ume

lime.

Barytes

barytes.

Magnefia

magnefia.

Oxyd of

zinc

zinc.

iron

iron.

manganefe

manganefe.

cobalt

cobalt.

nickel

nickel.

lead

lead.

tin

tin.

copper

copper.

biihiuth

bifmutb.

antimony

antimony. .

arfenic

arfenic.

filvcr

filver.

mercury mercury,

gold gold.

platioa platina.

Z 4 Sect.

! All Uwlc were lukBOwn to former chemilli — A,

560

ELEMENTS

Sect. XHV. — Obfervationj upon the Prttjic A-
cid, and its Combinations.

As the experiments which have been made
hitherto upon this acid feem ftill to leave a con-
fiderable degree of uncertainty with regard to
its nature, I fliall not enlarge upon its properties,
and the means of procuring it pure and diien-
gaged from combination, it combines with iron,
to which it communicates a blue colour, and is
equally fufceptible of entering into combination
with moft of the other metals, which are preci-
pitated from it by the alkalies, ammoniac, and

OF CHEMISTRY, 361

upon the nature of this fubftance, until the fub*
jed has been fiurther elucidated by a greater num«-
ber of experiments.

Sect. ^hV.^^Kecapitulationof the foregoing Ob"
fervations on the Acids^ and tbeir Combina^
tions ♦.

It was thought, that it might be conducive to
the convenience and information of the reader
to fubjoin the two following tables. The firft,
which is only a recapitulation of what is con-
tained in the foregoing fedions, gives a gene-
ral view of the order of the affinities of the fa-
lifiable bafes with the feveral acids, fo far as is
hitherto known. Such acids as have a fimilar
order of affinity with thefe bafes, are placed to-
gether, at the head of the fame column, and
thofe of which the order of affinity, between
them and the bafes, have not been hitherto afcer-
tained, are omitted.

The fecond table contains a fpecimen of a
general view of the new chemical nomenclature,
as applied to the neutral falts, both in Latin

and

* The whole of this feftion was added to the fecond edi-
tion by the Tranflator.

- I ?i E X T S

re £r^ r:Ij— n contains the

Li. K-^'if I the iKond is a lift of

TT-; Tjjj-.ri". I'ilii -.vh'ch thcfe

: ■ :'-■;; .i. .-iVx bii'cs, as pro-

'■■:: : :7i.i_iu.-:i j: thefc tenns
\:.-t"..- jri'.r,-.:: principles:
>■ i.'s.'ch;: .> r,i~\ c: Lutin no-
rd -c :'r.i: ^:":"~j French che-
: n;b;: :>.< rlir; i:f Bergman,
.- .V.~; ~:«s : ths ntth and
i :c.\H rr;*...h triRllation of

>'is. :>;« r.oxencla-
r'.ijx. 25 already

OF CHEMISTRY. 363

ever, can induce no ambiguity, as it mult be
generally underftood that no metal can enter
inta combination with an acid, unlefs it be pre-
vioufly oxydated.

TABLE

ELEMENTS

TABLE OF THE Acids ih the order ot
Affinity.

1 L

II.

in.

IV.

I9&MB NicHc

Sak^BWB.

Acetous, Acetic,

Nitro-murtacic

a.yi r..iii-

and Formic A-

Boracic Actd.

Acid.

dds.

|BSA<><.

••jo-

B.ryu.

Galea.

Arga.

UM.

Lixa.

Baryta.

Ammona.

TroB«.

Magnelia.

Oxyds o£

QriBk

C«l«.

Lisa.

Antimony.

■wj;;

Mapiefia.

Trona.

SUver.

.■Vrumodi.

AmiDona.

Arfenic.

'^f-

0»v>t of

OxTds of

Iron'.'

Baryta.

^^

Zinc.

Osyd of
Bifjnuth.

■1

OF CHEMISTRY.

365

V.

VI.

VII.

Phofphorous, Phof-

phoricy TungiUc,

Tartaroas, Oxalic^

Carbonic Acid.

Muriozic Acid.

and Saccho-iadic

'

Acids.

Galea.

Baryta.

• *■ - • *

Baryta.

Barjta.

Galea.

Lixa.

Magnefia.

Lixa.

Trona.

Liza.

Trona.

Galea.

Trona.

Magnefia.

Magnefia.

Ammona.

Ammona.

Arga.

Arga.

Arga.

Oxjds as in Coll. I.

Oxyds as in Coll. I.

Oxyds as in Coll. I.

VIII.

IX.

X.

Fluoric and Arfeniac

Citric Acid.

Pyro-lignoos Acid.

Acids.

Galea.

Baryta.

Galea.

Baryta.

Galea.

Baryta*

Magneiia.

Magnefia.

Lixa.

Lixa.

Lixa.

Trona.

Trona.

Trona.

Magnefia.

Ammona*

Ammona.

Ammona.

Ozjds as in Coll. 11.

Oxyds as in GoU. 11.

Oxyds as in Coll. II.

Arga.

omitting Tin, Nickel^
and Bifmuth.

Arga.

Arga.

XI.

XII.

XUI.

Pyro-mucous Acid.
Lixa.

Succinic Acid.

Pruflic Acid.

Baryta.

Lixa.

Trona.

Galea.

Trona.

Baryta.

Lixa.

Ammona.

Galea.

Trona.

Galea.

Magnefia.

Ammona.

Baryta.

Ammona.

Magnefia.

Magnefia.

Arga.

Arga.

Oxyds as in Coll. I.

Oxyds as in Coll. II.

Oxyds as in GoU. I.

placing Silver before

ting Silver, Gold,

Mercury.

^na«

306 ELEMENTS

TABLE OF TH£ Nomenclature

Acids.

Lavo.fier.

Latin.

Englifli.

I

j

f

Sulphurous.

Sulphuric.

Phofphorous.
Phofphoric.

Sulphis potaiTae
fodar

Sulphas calcis
magneCse

argillsB

Phofphis potalTBc
Phofphas fodsB

Sulphite of ponOi

offod.

of ammoniac

Sulphatoflime

ofmagnefia

of barytes

ofargiil

Phofphitc of potafli
Phofphat of foda

H

OF CHEMISTRY*

367

OF THE NbUTRAL SaLTS.

Propofed Alteration.

Latio.

Lixa fulphurofin
Trona fulphurofa
Ammona fulphurofa
Galea fulphurica
Magnefia fulphurica
Baryta fulphurica
Arga fulphurica
Lixa phofphorofa
TrcHia phofphoriqi
Ammona nitrofa
Argenta nitrica
Aura nitroxxca

Mercuria muriatica
Lixa murioxica

Trona boracica
Ammona acetofa
Cupra aceticn, &c«

Engliih.

Sulphurous lixa

trona

ammona

Sulphuric calca

magnefia
baryta

arga

Phofphorous lixa
Phofphoric trona
Nitrous ammona
Nitric filver
Nitroxic gold

Muriatic Mercury
Murioxic lixa

Boracic trona
Acetous ammona
j Acetic copper, &c.

PAB'^

OF CHEMISTRY.

377

The weight of a determinate magnitude of wa-
ter has been generally affumed as unity for this
purpofe J and we exprefs the fpecific gravity of
gold, fulphuric acid, &c. by faying, that gold is
nineteen times, and fulphuric acid twice the
weight of water, and fo of other bodies.

It is the. more convenient to alTume water as
unity in fpecific gravities, that thofe fubftances
whofe fpecific gravity we wifli to determine, are
mod commonly weighed in water for that pur-
pofe. Thus, if we wifti to determine the fpc-
cific gravity of gold flattened under the ham-
x^er,' and fuppofing the piece of gold to weigh
489 8|- grs. in the air *, it is fufpended by
means of a fine metallic wire under the fcale qf
a hydroftatic balance, fo as to be entirely im-
merfed in water, and again weighed. The
piece of gold in Mr Briflbn's experiment loft by
this means 253 ^r/. ; and as it is evident that
the weight loft by a "body weighed in water is
precifely equal to the weight of the water dif-
placed, or to that of an equal volume of water,
we may conclude, tliat, in equal magnitudes^
gold* weighs 4898-^ grs. and water 253 grs.
whictij reduced to unity, gives i.oooo as the
fpecific gravity of water, and 193617 for that
\)f gold. We may operate in the fame manner

with

* Vide Mr Briflbn's Eflay upoa Specific Gravity^ f
—A. 3

373 ELEMENTS

roughly comprehended. This want could not
have been fupplied from books ; for, befides
that there arc not any which dpfcribe the mo-
dcrn inftruments and experiments fufficiently at
large, any work that could have been confulted
would have prefented thefe things under a veiy
diflferviu order of arrangement, and in a dif-
ferent chemical language, which mufl. greatlj
tend to injure the main obje£l of my perform-

Inlluenced by thefe motives, I determined to
referve, for a third part of my work, a fummary
defctiptioo of all the inftruments and manipu-
lations relative to elementary chemiftry. I con-
fider it as better placed at the end than at the
bei^inning of tlie book; becaufe.otherwife, I muft

OF CHEMISTRY. 571

' ' n*-' ^^ ••-» S' >*

I am fer from pretending by^ it taTet a:fide
the neceflity of attendance n^on leSltif 6s and la*
boratories, for fuch as 'vititix to acquire accurate
knowledge of the fcience bf cheiniftSy. Thefe
ihould familiarife themf^^esto tbe'eroploynient
of apparatus, and to the performance jcif dxperi*
ments by a£kisd experience. Nibii i^ hi intel-
leilu quod non prius fuerit in fenfu^ the motto
which the celebrated Rouelle caufed to be paint-
ed in large charaders on a confpicaous part of
tiis laboratory, is an important truth never to
be loll fight of either by teachers or ftadents of
chemiftry.

. Chemical operations may be naturally divided
iflto feveral clafles, according to the purpofes
they are intended for performing. Some may
be confidered as purely mechanical, fuch as the
determination of the weight and bulk of bodies,
trituration, levigation, fearching or fifting, wafh-
ing, filtration, &c. Others may be confidcred
as real chemicsd operations, becaufe they are per-
formedjby means of chemical powers and agents;
fuch are fodution, fufion, &c. Some of thefe
are intended for feparating the ekm^its of bo-
dies from each other, fome for reuniting theie
elements together, and fome, as combulUon, pro-
duce both thefe effeds during the fame pr^-
cefs.

Without rigoroufly endeavouring to follow
^ above method, I mean to give a detail of

A a 2 the

37f>

ELEMENTS

roughly comprehended. This want could not
have been fupplied from books ; for, befides
that there are not any which defcribe the mo-
dern inftruments and experiments fufficiently at
large, any work that could have been confulted
would have prefented thefe things under a very
different order of arrangement, and in a dif-
ferent chemical language, which muft greatly
tend to injure the main objedl of my perform-
ance.

Influenced by thefe motives, I determined to
refervc, for a third part of my work, a fummary
defcription of all the inftruments and manipu-
lations relative to elementary chemiflry. I con-
fider it as better placed at the end than at the
beginning of the book ; becaufe, otherwife, I muft
have been obliged to fuppofe the reader conver-
fant with circumftances which a beginner cannot
know, and to become acquainted with which
he muft have previoufly read the eliimentary
part. The whote of this third part may, there-
fore, be confidered as refembling the explana-
tions of plates, which are ufually placed at the
end of academic memoirs, that they may not
interrupt the connexion of the text, by lepgth-
pned defcription.

Though I have taken great pains to render
this part clear and methodical, and have not
omitted any eflenliiU inftrument or apparatus,

I

i

OF CHE MIS TRY. 571

. I

I am fer from pretending by it tVTet afide
the neceflity of attendance upon leShifes and la*
boratories, for fuch as ^iih to acqitire accurate
knowledge of the fcience xft cheinift^y. Thefe
ihould familiarife themf^^esto the eraploymeht
of apparatus, and to the performance it^f experi*
ments by a£kisd experience. Nibii ejfi (n Intel"
leSlu quod non prius fuerit in fenfu^ the motto
which the celebrated Rouelle caufed to be paint-
ed in large charaders on a confpicaous part of
his laboratory, is an important truth never to
be loll fight of either by teachers or ftudents of
chemiilry.

Chemical operations may be naturally divided
into feveral clafles, according to the puipofes
they are intended for performing. Some may
be confidered as purely mechanical, fuch as the
determination of the weight and bulk of bodies,
trituration, levigation, fearching or fifting, wafh-
ing, filtration, &c. Others may be confidcred
as real chemicsd operations, becaufe they are per-
formedjby means of chemical powers and agents;
fuch are fodution, fufion, &c. Some of thefe
are intended for feparating the ekm^its of bo-
dies from each other, fome for reuniting theie
elements together, and fome, as combufiion, pro-
duce both thefe effeds during the fame pr^-
cefs.

Without rigoroufly endeavouring to follow
the above method, I mean to give a detail of

A a 2 .the

57*

E L E M E ?J ,T S

the chemical operations in fuch order of arrange-
ment as feeniB beft calculated for conveying in-
ftruiition. 1 (hall be more particular in defcri-
bing the apparatus connedled with mod«ra che-
miftry, becaufe thefe are hitherto little known
by men wjio have demoted much of their time
to chemiftry, and eyeii by m^ny profeObcs of
the fcience.

)o Ihi'^h -. rtip cj unm I .'

OF CHEMISTRY. 373

\

C H A P. I.

1

Of the Injlruments necejjary for determining the
Abfolute and Specific Gravities of Solid and
Liquid Bodiej4

T'^ltE bed metliQci hithetto known for deter-
mining the qudntitie^ of fabftaHces fub-i
tnitted to chenKical experiment, ot refuiting frofti
them, is by means of accurately conlbru(Sed' beams
and fcales, with properly regulated weights ;
which well known operation is called weighing.
The denomination and quantity of the weight
ufed as an unit or ftandard for this purpof^ are
extremely arbitrary, and vary, not only in diffe-
rent kingdoms, but even in different provinces
of the fame kingdom, and in different cities of
the fame province. This variation is of infinite
confequence to be well underftood in commerce
and in the arts j but, in cheniiflry, it is of no
moment what particular denomination of weight
be employed, provided the refults of experi-
ments be expreffed in convenient fradlions of
the fame denomination. For this purpofe^ un-
til all the weights ufed in fociety be reduced to
the fame ftandard, it will be ftifficicnt for che-

Aa3 mffts,

■J

374 E L t M L N T S

au&tf in tiiScrcDt psrts, to me the common p
of their own coontiy, as the unit or I
and to exprcfs all its fradioDad pans in decimals;
inftead of the arbitrary diritions now in nfc.
By this nietbod the chemifbof allcoDOtries will
be thoroughly undcrflood by each other ; as, al-
though the abfolute weights of the ingredients
and producls cannot be known, they will readfly,
and without caiculatioo, be to able to detenniue
the relative proportioDs of thefe to each otbec
with the utmoft accuracy ; fo that in this way wc-
IhaU be poiTdled of an univerfal language for this
part of chemiftry.

With this view I have long projeded to have
the pound divided into decimal fradlioos, and I
hare of late fucceeded through the afRflance of
Mr Fourche, balance-maker at Paris, who has
executed it for me with great accuracy and judg-
ment. 1 recommend to all who carry on expcri>
ments to procure fimilar divtfions of the pound,
which they will find both eafy and 6mple in its
application, with a very finall knowledge of de-
cimal fractions *.

As

• Mr Lavoifier girt!, in this pant of tut work, very
accurate direAioos for redacing the common fubdivifioot-
of the Freoch pouad into deciaal &a%ons, and W» Dtrfitf
by means of tables, fubjoincd to this 3d part. As tbefe
inflruflioas, ood the table, would be uIcIaTs to the BrhiSl
cheifiii), from the di&reace between the fubdivifioos of the
Frencb and Troy pounds, I have omitted them, but bave
fubjoiasA

I

I
I

As the ufefiilnefs and accuracy of chemiftry
depend entirely upon the detcrminntion of the
weights of the ingredients and produ^s, both
before and after experiments, too much pieci-
fion cannot be employed in this part of the fub-
jcfl ; and, for this purpofe, we muft be provided
with good inftruments. As we are often obli-
ged, in chemical proceffes, to afcertain, within
a grain or lefs, the tare or weight of large and
heavy inftruments, we muft have beams made
with peculiar nicety by accurate workmen,
and thefe muft always be kept apart from the
laboratory, in feme place where the vapours of
acids, or other corrolive liquors, cannot have
accefs, otherwife the fteel will ruft, and the ac-
curacy of the balance be dcftroyed. I have
three fets, of dilTerent fixes, made by Mr I'on-
tin with the utmoft nicety, and excepting thofe
made by Mr Ramfden of London, 1 do not
think any can compare with them for precilion
and fenfibility. The largeft of thcfe is about
three feet long in the beam for large weights,
up to fifteen or twenty pounds ; the fecond, for
weights of eighteen or twenty ounces, Is exaift
A a 4 to

fubjoined in tlie appendix accurate rules for convening the
one denomination into the other, together ^vith tables for
reducing the various divllions of pur Troy pound into de*
cimals, and for converting (befe decimals into the otdi-

1 nary

divifions.— T.

ELEMENTS

t'ari, joined to experiments with certaio re-
Egcr.;-:*, is one of the bcft for determining the
cuilirv cf naters, and is even capable of point-
ing cu: differences which efcape the moft accu-
rate chemical analyfis. I (hall, at fome future
period, give an account of a very extenfive fet
of experiments which I have made upon this
lubjeiil.

Thefe metallic hydrometers are only to be
iilcd for determining the fpccific gravities of
fuch niiters as contain only neutral falts or al-
kaline fubftanccs; and they may be conftruded
with different degrees of ballaft for alkohol and
other fpiritous liquors. When the fpecific gra-
vities of acid liquors are to be afcertained, we
muft ufe a glaft hydrometer, as reprefented

OF CHEMISTRY. 377

The weight of a determinate magnitude of wa-
ter has been generally aflumed as unity for this
purpofe ; and we exprefs the fpecific gravity of
gold, fulphuric acid, &c. by faying, that gold is
nineteen times, and fulphuric acid twice the
weight of water, and fo of other bodies.

It is the. more convenient to aflume water as
unity in fpecific gravities, that thofe fubftances
whofe fpecific gravity we wifh to determine, are
moft commonly weighed in water for that pur-
pofe. Thus, if we wifti tp determine the fpe-
cific gravity of gold flattened under the ham-
tqeTf\ and fuppofing the piece of gold to weigh
4898^ grs. in the air *, it is fufpended by
means of a fine metallic wire under the fcale of
a hydroftatic balance, fo as to be entirely im-
merfed in water, and again weighed. The
piece of gold in Mr Briflbn's experiment loft by
this means 2.53 ^rj. ; and as it is evident that
the weight loft by a "body weighed in water is
precifely equal to the weight of the water dif-
placed, or to that of an equal volume of water,
we may conclude, that, in equal magnitudes,
gold*\Veighs 4898^ grs. and water 253 ^rs.
whicti^ reduced to unity, gives i.cooo as the
fpecific gravity of water, and 19.3^17 for that
\)f gold. We may operate in the fame manner

with

* Vide Mr BriiTon';; Eilay upoa Specific Gr&vity, p. 5.

370

ELEMENTS

roughly comprehended. This want could nw
have been fupplied from books ; for, befides
that there are not any which defcribe the mo-
dern inftruments and experiments fufficienily at
large, any work that could have been confulted
would have prefented thefe things under a very
different order of arrangement, and in a dif-
ferent chemical language, which muft greatly
tend to injure the main objefl of my perform-
ance.

Influenced by thefe motives, I determined to
referve, for a third part of my work, a fummary
dcfcviptioo of all the inftruments and manipu-
lations relative to elementary chemiftry. I con-
fider it as better placed at the end than at the
beginning of the book; becaufe, otherwife, I muft
have been obliged to fuppofe the reader conver-
fant with circumftances which a beginner cannot
know, and to become acquainted with which
he muft have previoufly read the elementary
part. The whole of this third part may, there-
fore, he conHdered as refembling the explana-
tions of plates, which are ufually placed at the
end of academic memoirs, thai they may not
interrupt the connexion of the test, by length-
ened dcfcription.

Though 1 have taken great pains to render
this part clear and methodical, and have not
pmitted any cflentiiil jnftrument or apparatus,

I

OF CHEMISTRY- 383

The jars or bell-glafl*es are filled with water in
this deep part, and, being turned with their
mouths downwards, are afterwards fet upon the
flielf ABCD, as Ihewn Plate X. Fig. i. F.— The
upper parts of the fides of the ciftem above the
level of the ihelf are called the rim or borders.

The ciftem ought to be filled with water, fo
as to ftand at leaft an inch and a half deep over
the ihelf, and it fhould be of fuch dimenfions as to
admit of at leaft one foot of water in every direc-
tion in the well, orciftern. The fize above defcrib-
ed is fufficient for ordinary occafions ; but it is of-
ten convenient, and even neceflary, to have more
room ; I would therefore advife fuch as intend
to employ themfclves ufefuUy in chemical expe-
riments, to have this apparatus made of confide-
rable magnitude, where their place of operating
will allow. The well of my principal ciftern holds
four cubical feet of water, and its flielf has a fur-
face of fourteen fquare feet ; yet, in fpite of this
fize, which I at firft thought immoderate, I am
often ftraitened for room.

In laboratories, where a confiderable number
of experiments are performed, it is neceflary to
have feveral lefler ciftems, befides the large one,
which may be culled the general magazine ; and
even fome portable ones, which may be moved
when neceflary, near a furnace, or wherever
they may be wanted. There are likewife fome
'q^rations wliieb dirty the water of the appara-
tus^

3S4

ELEMENTS

tus, and therefore require to be carried on in cif-
terns by themfelves.

It were doubtlefs confldcrably cheaper to ufe
tillenis of wood, fimply dove-tailed, or iron-
bound tubs, inilead of being lined with lead or
copper ; and in my firH experiments I ufed them
made iu that way, but I foon difcovcred their
inconvenience. If the water be got alwajrs
kept at the fame level, fucb of the ^ovccails as
:ire kft dr^- (hrint, and, when mve water is
added, it efcapes through the joias, and runs
out. I

We employ cryftal jars or bell gfafles, PI. V.
Fig. 9. A. for containing the gjaflcs in this ap-
paititus; and, for tranfporting thefe, when full
of gus, from one ciftcrn to another, or for keep-

OF CHEMISTRt.

393

broad and ten inches thick, and caufe it to be
hollowed out, as at m n. Fig. 5. about four inches
deep, as a refervoir for the mercury ; and, to be
able more convenientlj' to fill the jars, cut the
gutter T V, Fig. 3. 4. and 5. at leaft four inches
deeper; and as this trench m^y fometimes prove
troublefome, it is made capable of being covered
at pleafure by thin boards, which flip into the
grooves xy. Fig. 5. I have two marble cifternS
upon this conllruAion, of different fizes, by
which t can always employ one of them as a re-
fervoir of mercury, which it preferves with more
fafety than any other veflel, being neither fubjet^
to overturn, nor to any other accident. We 0-
perate with mercury in this apparatus exaflly as
with water in the one before defcribed ; but the
bell-glalTes muft be of fmaller diameters, and
much' UroDger ; or we may ufe glafs tubes, ha-
ving their mouths widened, as in Fig. 7. ; thefe
are called eudiometers by the glafs-men who felt
them. One of the bell-glafies is reprefented
Fig. 5. A. Handing in its place, and what is cal-
led a jar is engraved at f ig. 6.

The mercurial pneumato-chemical apparatus
is neceflkry in all experiments wheren the difen-
gaged gafles are capable of being abforbed by
water, ;is i$ frequently the cafe, efpecially in all
[ combinations, excepting thofe of metals, in fer-
mentation, &c.

fib

SECT.

336

ELEMENT^

SECT. II.

Of tbt Gaxometer.

I glre the name ofjazometer to an ioArameiit
which I invented, and caufcd to be cooflnided^
for the purpofe of a kind of bellows, which might
fiirnUh on unifbrtD and continued ftream of oxy-
gen g-os in experiments of fiifion. Mr Meufnier
and I huve Gnce made very confiderable correc-
tions and additions, haring converted it into what
■uy be called an maher/al iiifintment, without
which it is hardly poffible to perform moft of the
very exact experimeots. The name we have gi-
Tcn the inAiument indicates its intention for
roc-Al'iiring the Tolumc or quantity of cas fub-

61* CHEMISTRY.

38?

tiotl, the parts of tbefe wheels which fupport
the axis of the beam are covered with platetiof
poliAied rock^cryftaL The whole of this machi-
nery is fixed to the top of the foUd column of
wood BC, Fig. I. To one extremity D of the
beam, a {bale P for holding weights is fufpend-
ed by a flat chain, which applies to the curvature
of the arc nDo, in a groove made for the pur-
pofe. To the other extremity E of the beam is
applied another flat chain, i k m^ To conllruAed,
as to be incapable of lengthening or fhortening,
by being lefs or more charged with weight ; to
this chain, an iron trivet, with three branches,
a 1, c I, and b i, is ftrongly fixed at i, and thefe
branches fupport a large inverted jar A, of ham-
mered copper, about i8 inches diameter, and
20 inches deep. The whole of this machine is
reprefented in perfpedive, PI. VIIX. f igi. and
Fl. IX. Fig. 2. and 4. give perpendicular feo
tions which fhew its interior ftrucEiure.

Round the bottom of the jar, on its outfide,
is fixed, Fl. IX. Fig. 2. a border divided into
compartments i, 2, 3, 4, &.c. intended to re-
ceive leaden weights feparately reprefented i,
3, 3, Fig. 3. Thefe are intended for increafing
the weight of the jar when a confiderable pref-
fure is requifite, as will be afterwards explain- -
ed, though fuch neceffity feldom occurs. The
cylindrical jar A is entirely open below, d e,
Fl. IX. Fig. 4. ; butisclofed above with a copper
fi b a lid.

388

ELEMENTS

lid, a b c, tipeti at bf, and capable of being {hut
by the cock^. This lid, as may be feen by in-
fpeiSing the figures, is placed a few inches within
the top of : he jar, to prevent the jar from being
ever entirely immerfcd in the water, and covered
over : Were I to have this inftrumcnt made over
again, I fhould caufe the lid to be confiderably
more flattened, fa as to be almoft level. This
jar or rcfervoir of air is concained in the cylin-
drical copper veffel LMNO, PI. VIII. Fig I.
filled with water.

In the middle of the cylindrical veflet LMNO,
PI. IX. Fig. 4. are placed two tubes s t, x y,
which are made to approach each other at their
upper extremities t y ; thcfe are made of fuch a
length as to rife a Httlc abo^e the upper edge
LM of the veflel LMNO, and when the jac abide
touches the bottom NO, their upper ends enter
about half an inch into the conical hollow b^
leading to the ftop-cock j.

The bottom of the velTel LMNO is reptefent-
cd PI. IX. Fig. 3. in the middle of which a
fmail hollow hemifpherical cap is foldered. which
nay be confidered as the broad end of a fuanel
reverfed ; the two tubes / I, xy. Fig. 4. are ad-
apted to this cap at s and -v, and by this meaas
cummunicate wiih the tubes mm, nn, oo.pp, Fig.3.
which are fixed horizontally upon the bottom
of the veiTd, and all of which terminate in, and
arc united by, the fpherical cap ix. Three of
thcfe tubes are continued out of the veflel, as in

PL

OF CHEMISTRY.

3*9

PI. VIII, Fig. I. The firft marked in that figure
1, 1, 3, is inferted at its extremity 3, by means
of an intermediate ftop-cock 4, to the jar V,
which (lands upon the flielf of a fmall pneumatp-
chemical apparatus GHIK, the infide of which
is fhewn PI IX. Fig. i. The fecoiid tube is ap-
plied againft the outfide of the veflel LMNO from
6 to 7, is continued at 8, 9, ig, and at 11 h en-
gaged below the jar V. The forijier of thefe
tubes is intended for conveying gas into the
machine, and the latter for condut^ing finail
.quantities for trials under jars. .The gas is made
either Vi flow into or out of the machine, accord-
ing to the degree of preflure it receives; and
this preflure is varied at pleafure, by loading
the fcale P lefs or more, by means of weights.
When gas is to be introduced into the machine,
the preflure is taken off, op even rendered ne-
gative ; but when gas is to be expelled, a pref-
fure is made with fuch degree of force as is found
necellary.

The third tube 12, 13, 14, 15, is intended for
conveying air or gas to any neceflary place or
apparatus for coraburtions, combinations, or any
other experiment in which it may be reijuired.

To explain the ufe of the fourth tube, I jnuft

I enter into fiame difcuffions. Suppof^l the vefl'el
LMNO, PI. Vlll. Fig. I. full of water, and the
jur A partly filled with gas and pirtly with
crater ; it is erident that the weights in tht ba-
B b ^ fon

I
I
I

390

ELEMENTS

fon P may be fo adjufted, as to occafion An
aft t,'quiUbrium between the weight of the bafoD
and of the jar, fo that the external air (hall not

, tend to enter into tlie jar, nor the gas to efcape
from it ; and in this cafe the water will (land

_ exaflly at the fame level both within and with-
out the jar. On the contrary, if the weight in
the bafon P be dirainiflied, the jar will then prefi
downwards from its own gravity, and the water
will ftand lower within the jar than it does
without ■, in this cafe, the included air or gas
will fuffer a degree of coniprelTion above thi
experienced by the external air, exaftly propoi
tioned to the weight of a column of water, equi
to the difference of the external and intei
i'urfaces of the water.

From thefe refleclions, Mr Meufnier contrived
a method of determining the exaft degree of pref-
fure to which the gas contained in the jar is at
any time expofed. For this purpofe, he employs
a double glafs fyphon ig, 20, 21, 22, 23, firmly
cemented at ig and 23. The extremity 19 of
this fyphon communicates freely with the water
in the external vefiel of the machine, and the
extremity 23 communicates with the fourth
tube at the bottom of the cylindrical veffel, and
confequently, by means of the perpendicular
tube St, PL IX. Fig. 4. with the air contained in
the jar. He likewife cements, at 16, PI. VIII.
Fig. I.- another glafs tube i6, 17, 18, which
3 communicate)

gas

thtlj^H

poi^^l

OF CHEMISTRY. 391

^communicates at 16 with the water in the exte-
rior veflel LMNO, and, at its upper end 18, is
open to the external air.

By thefe feveral contrivances, it is evident
that the water mud ftand in the tube 16, 17, 18^
at the fame level with that in the ciftern LMNO ;
and, on the contrary, that, in the branch 19,
20, 21, it muft ftand higher or lower according
as the air in the jar is fubjeded to a greater or
lefler preflure than the external air. To afcer-
tain thefe differences, a brafs fcale divided into
inches and lines is fixed between thefe two
tubes. It is readily conceived that, as air, and
all other elaftic fluids, muft increafe in weight
by compreflion, it is neceflary to know their
degree of condenfation to be enabled to calcu-
late their quantities, and to convert the meafure
of their volumes into correfpondent weights;
and this objed is intended to be fulfilled by the
contrivance now defcribed.

But, to determine the fpecific gravity of air or of
gaffes, and to afcertain their weight in a known
volume, it is neceflary to know their tempera-
ture, as well as the degree of preflure under
which they fubfift ; and this is accompliflied by
means of a fmall thermometer, ftrongly cement-
ed into a brafs collet, which fcrews into the lid
of the jar A. This thermometer is reprefented
iejpaiitely, PL VIIL Fig. 10. and in its place
t^g. and PL IX. Fig. 4. The bulb is

nr-

ELEMENTS

in the infide of the jer A, and its graduated ftalk
rifes on the outlide of the Ijd.

The pra-flice of gazometry would ftill have
laboured under great difficulties, without farther
precautions than thofe above defcribed. When
the jac A finks in the water of the cifteni
LMNO, it muft lofe a weight equal to that of
the water which it difplaces ; aad confequcntly
the compreflion which it makes upon the con-
tained air or gas muft be proportionally dimi-
niHicd. Hence the gas furnilhed, during experi-
meius from the machine, will not have the fame
dcnfuy towards the end that it had at the begin-
ning, as its fpecific gravity is continually dimi-
nifliing. This difference may, it is true, be de-
termined by calculation ; but this would have

OF CHEMISTRY. 393

Cal, this box gravitates to neither fide ; but,
when the jar A finks into the ciftern LMNO,
£0 as to make the beam incline to that fide, it is
evident the loaded box 28, which then pafTes
beyond the center of fufpenfion, muft gravis
tate to the fide of the jar, and augment its
preflure upon the included air. This is in^
creafed in proportion as the box is raifed to*
wards 7>7t becaufe the fame weight exerts a
greater power in proportion to the length of
the lever by which it adls. Hence, by moving
(he box a 8 along the rod a6, 27, we can aug-
ment or diminiih the cprredtion it is intended
to make upon the preflure of the jar ; and both
experience and calculation ihew that this may
be made to compenfate very exadly for the lofs
of weight in the jar at all degrees of preflure.

I have not hitherto explained the mod im-
portant part of the ufe of this machine, which
is the manner of employing it for afcertaining
the quantities of the air or gas furnifiied during
experiments. To determine this with the mofl:
rigorous precifion, and likewife the quantity
fupplied to the machine from experiments, we
fished to the arc which terminates the arm of
the beam E, PI. VllL Fig. i. the brafs fedor
/ 97, divided into degrees and half degrees,
which confequently moves in common with th^
beam ; and the lowering of this end of the
beam is meafured by the fixed index 29, 30,

which

394

ELEMENTS

which has a Nonius giving hundredth parts G
degree at its extremity 30.

The whole particulars of the different part
of the ahove defcribed machine are reprefented
in Plate VUI. as follow.

Fig. 2. Is the flat chain invented by Mr Vau-
canfon, and employed for fufpending the fcale
or bafon P, Fig. i. ; but, as this lengthens or
ftjortens according as it Is more or lefs loaded, it
would not have anfwered for fufpending the jar
A. Fig. r.

Fig. 5. Is the chain ti m, which in Fig. i.
fuflains the jar A. This is entirely formed of
plates of polilhed'iron interlaced into each other,
and held together by iron pins. This chain
does not lengthen in any fenfible degree, by any
weight it is capable of fupporting.

Fig. 6, The trivet, or three branched flir-
rup, by which the jar A is hung to the balance,
with the fcrew by which it is fixed in an accu-
rately vertical pofition.

F'S- 3- The iron rod 26, 27, which is fixed
perpendicular to the center of the beam, with its
box 28.

Fig. 7. & 8. The friftion-wheels, with the
plates of rock-cryftal X, as points of contaft by ,
which the fridionof the axis of the lever ofth»i
balance is avoided.

Fig-

OF CHEMISTRY. 395

Fig. 4. The piece of metal which fupport»
the axis of the fridion- wheels.

Fig. 9. The middle of the leYer or beam,
with the axis upon which it moves.

Fig. 10. The thermometer for determining
the temperature of the air or gas contained in
the jar.

When this gazometer is to be ufed, the cif-
tern or external veffel, LMNO, PI. VIII. Fig, 1.
is to be filled with water to a determinate height,
which fhould be the fame in all experiments.
The level of the water Ihould be taken when the
beam of the balance (lands horizontal ; this
level, when the jar is at the bottom of the cif-
tern, is increafed by all the water which it dif-
places, and is diminifhed in proportion as the
jar rifes to its higheft elevation. We next en-
deavour, by repeated trials, to difcover at what
elevation the box 28 mud be fixed, to render
the preflTure equal in all fituations of the beam.
I fhould have faid nearly, becaufe this correc-
tion is not abfolutely rigorous ; and differences
of a quarter, or even of half a line, are not of
any confequence. This height of the box 28
is not the fame for every degree of prefTure, but
varies according as this is 6f one, two, three, or
more inches. All tbefe fhould be regiftered with
great order and precifion.

We next take a bottle which holds eight or
(en pints^ the capacity of which is very accu-
rately

t I

ELEMENTS

rately determined by weighing the water it is
capable of containing. This bottle is turned
bottom upwards, full of water in the ciflern of
thepneuraato-chemicalapparatusGHlK., Fig- i.
and is fet on its mouth upon the flielf of the
apparatus, inftead of the glafs jar V, having the
extremity ii of the tube 7, 8, g, 10, 11, jn-
ferted into its moulli. The machine js fixed at
%tTQ of preflute, and the dcgTee marked by the
index 30 upon the fetitor m / is accurately ob-
ferved ; then, by opening the ftop-cock 8, and
pretling a little upon the jar A, as much aic it
forced into the bottle as fills it entirely. The
degree marked by the index upon the fedtor is
now obfervcd, and we calculate what number
of cubical inches correfpond to each degree.
We then fill a i'econd and third bottle, and fo
on, in the fame manner, with the fame precau-
tions, and even repeat the operation feveral times
with bottles of different Czes, till at laft, by ac-
curate attention, we afccvtain the e](acl gage or
capacity of thejgr A, in qll its parts; but it is
better to have it formed at firft accurately cy-
lindrical ; by which we avoid thefe calculations
and ejlimates.

The inflrument I have been defcribing waa
conAru<3ed with great accuracy and uncomnion
Ikill by Mr Meignie junior, engineer and phyfi-
cal iuftrument-msker. It is a moft valuable in-
flrument, from th? great number oi pprpofes to
a which

/

or CHEMISTRT. 397

which it is applicable ; ftnd, indted^ there arc
many e^periinents whioh are almoft impollibk
to be perfbnBcd without it« It becomes ex*
penfive, becaufe, in many experiments, fuch as
the formation of water and of nitric acid^ it b
abfblutely necsflary to em^doy two of the iame
machines. In the pre&nt advanced ftate of chc^^
miftrjr, very expenfive and complicated inftru^
ments are become - indi^nfably necefTary, for
afcertaining the analyfis and fynthefis of bodies,
with the requifite precifion as to quantity and
proportion ; it is certainly proper to endeavour
to Amplify thefe, and to render them left coftly ;
but this ought by no means to be attempted at
the expence of their cooveniency of application,
and much lefs of their accuracy.

SECT. III.

Sof^^ other Mttbods bf Medfuring the Volufne of

'Gaffes.

The gasometer defcribed in die foregoing
fe&ion is too coftiy and too compliciEited for be**
ing generally ufed in laboratories for meafuring
the gaffes, and is not even applicable to every
circumftance of this kind. In nuttierous ferie^
of experiments, more iintple and itiore readily

applicable

ELEMENTS

apptkable SKCbods onift be employed. For tkts
parpole I (hall ddcribe tbe means I vScd belbie
I was in poUeffion of a gazatneter, and whk^ I
ftiU uie ia pretercnce to it in tbe onliinr7 amtb
oitnj experinwnts.

Soppofe chat. ancT an experiment, there is ■
refidanm of gas, ncicber ablbrbable by aikaii nor
water, coDlained in the upper part of tbe jar
AEF, PL IV. Fig. 3. Handing on tbe fcelt of a
poeomata-cbeinical apparatio, of which we wiih
to afcertain tbe qaantity ; we muft &i& mark the
faeigfat to which tbe mercnry or water rifes in
the jar with great exacineis, by means of flips
of paper palled in ieveral parts round the jar.
If we have been operating in mercury, we be-
gin by difplacing the mercury from tbe jar, by
introducing water in its ftead. This is readily
done by filling a bottle quite full of water ; ha-
ving Aopped it with your finger, turn it up, and
introduce its mouth below the edge of tbe jar ;
then, turning down its body again, the mer-
cury, by its gravity, fails into the boltle, and
the water riles in the jar, and takes the place
occupied by the mercury. When this is ac-
compliHied, pour fo much water into the cif-
tern ABCD as will ftand about an inch over the
farfacc of the mercury ; then pafs the diih BC,
PI. V. Fig. g. under the jar, and carry it to the
water ciftern, Fig. 1. and 2. We here ex-
change the gas into another jar, which has been
previoufly

OF CHEMISTRT. 399

previoufly graduated in the manner to be after-
wards defcribed ; and we thus, judge of tho
quantity or volume of the gas by means of the
degrees which it occupies in the graduated jar.

There is another method of determining the
volume of gas, which may either be fubftituted
in place of the one aboye defcribed, or may be
ufefully employed as a correction or j)rGof of
that method. After the air or gas is exchanged,
from the firfl jar, marked with flips of paper,,
into the graduated jar, turn up the mouth of
the marked jar, and fill it with water exadly to
the marks £F, PI. IV. Fig. 3. and by weighing
the water, the volume of the air or gas it con-
tained may be determined ; allowing one cubical
foot or 1728 cubical inches, French meafure, for
each 70 libs. French weight, or the fame cubical
volume in Englifh meafure for each 75.84 libs.
Englifli Troy, of the water.

The manner of graduating jars for this pur-*
pofe is very eafy, and we ought to be provided
with feveral of different fizes, and even feveral
of each fixe, in cafe of accidents. Take a tall,
narrow, and ftrong glafs jar, ■ and, having filled
it with water in the ciftern, PL V. Fig. i. place
it upon the ftielf ABCD ; we ought always to ufe
the fame place for this operation, that the level
of the fhelf may be always exadly fimiiar, by
which almoft the only error to which this pro-
ceis is Lable will be, avoided. Then take a nar-
., . row-

4^3

ELEMENTS

pofe that under the jar A, PI. IV. Fig. -j. i»
contained a quantity of different gaffes mixed
together, and ftanding over mercury ; we begin
by marking with flips of paper, as before direc-
ted, the height at which the mercury ftanda
within the g!afs ; and then introduce about a cu-
bical inch of water into the jar, which will fwim
over the furfece of the mercury ; If the miicture
of gas contains any muriatic or fulphurous acid
gas, a rapid and coniiderahle abibrptton will
inftantly take place, from the ftrong tendency
thefe two gaffes have, efpecially the former, to
combine with, or he abforbed by water. If the
water only produces a flight abforptton of gas,
hardly equal to its own bulk, we conclude, that
the mixture neither contains muriatic acid, ful-
phuric acid, or ammoniacal gas, hut that it con-
tains carbonic acid gas, of wliich water only ab-
I'orbs about its own bulk. To afcertain this
conjei5ture, introduce fome folution of cauftic
alkali, and the carbonic acid gas will be gra-
dually abforbed in the courfe of a few hours ;
it combines with the cauftic alkali or potafb,
and the remaining gas is left almoft perfefllj
free from any fcnfible refiduum of carbonic acid
gas.

After each experiment of this kind, we muft
carefully mark the height at which the mercury
ftands within the jar, by flips of paper paAei
on, and varniflied over when dry, that they I

OF CHEMISTRY. 401

* dr. 15. ^r/. of mfercttry* which exadlly cor-
f cfpond to a cubical inch of that metaL

This method of determining the rolumc 6f dit
or gas, by roeans of a graduated jar, has the ad-
vantage of not requiring any corredibn for the
^fierence of height between the. fur face of the
water within the jar, and in the ciftern ; but if
requires corredioos with refpeS to the height
of the barometer, and thermometer. But, when
we aicertain the volume of air by weighing
the water which the jar is capabie of contain-*
ing, up to the mai^ks EF, it is neceflaty to make
a farther corredion^ for the difference between
the furiace of the wiater in the ciltern, and the
height to which it rifes within the jar. This
will be explained in tib€ fifth fedion of this
chapter*

SECT. Vt. :.:

Of the Meibad of Separatifig tbe different Gqfes

from each otben •

As experiments often produce two, thre^ ot
more fpecies of gas, it is necefla^y to be able to
feparate thefe from each otber^ that we may af<^
certain the quantity and (pecie^ of each. Sup-

C c pofc

Tf^ri

4=4

ELEMENTS

furface with a white flame, we conclude it to he
pure hydrogen gas ; if this flame is blue, we
judge it conGfts of carbonated hydrogen gas;
and, if it takes fire with a fuddeii deflagration,
that it is a mixture of oxygen and hydrogen gas.
If, again, upon mixing a portion of the relida-
um with oxygen gas, red fumes are produced,
we conclude that it contains nitrous gas.

Thefe preliminary trials give Tome general
knowledge of the properties of the gas. and
nature of the mix-ture, but are not fufficient to
determine the proportions and quantities of the
feveral gaflTes of which it is compoled. For this
purpofe all the methods of analyfis muft be em-
ployed ; and, to. direA thefe properly, it is of

OF CHEMISTRY. 405

oxygen gas are fucceffively added, till no far-
ther deflagration takes place, and till the greateil
poflible diminution is produced. By this procefs
water is formed, which is immediately ablbrbed
by the water of the apparatus -, but, if the liy*
drogen gas contain carbon^ carbonic acid is form-
ed at the fame time, which is not abforbed fo
quickly ; the quantity of this i^ readily afcertain-
ed by affifting its abforption, by means of agita-
tion. If the refiduum contains nitrous gas, by
adding oxygen gas, with which it combines into
nitric acid, we can very nearly afcertain its quan-
tity, from the diminution produced by this mix-
ture.

I confine myfelf to thefe general examples,
which are fuflicient to give an idea of this kind
of operations ; a whole volume would not ferve
to explain every poffible cafe. It is neceflary to
become familiar with the analylis of gafles by
long experience ; we mult even acknowledge
that they moflly polliefs fuch powerful affinities to
each other, that we are not always certain of ha«
ving feparated them completely. In tfaofe cafes,
we muft vary our experiments in every poffible
point of view \ adding new agents to the com-
bination, and keeping out others, and muft con-
tinue our trials, till we are certain of the troth
and exudtitude of our conclufions.,.. ,

, ■' ■ iliT Lr-

Cc 3 •■•'•^

— • f

4C.6

ELEMENTS

SECT. V.

Of the neceffary Corrections upon the Volume aftbe
Gaffes, according to the Prejiire of the jitnm-
fpbere.

AH claflic fluids arc compreflible or contlen.
flble, in proportion to the weight with which
they are laj^dcd. Perhaps this law, which is af-
certained by general experience, may fufler fome
irregularity when thefe fluids aje under a degree
of cDndeiiiatlQn ahnoft fufTicient to reduce them
to tlfc lifjuid lUte, or when either in a ftatc of
extreme rarefadion or condenfulion ; but \vc fel-
(loni approach either of thefe limits with mofl: of
the galTes wliich we fubmit to our experiments.
1 undcrdand thiii propofition of gaffes being com-
preffible, in proportion to their fuperincumbent
weights, as follows :

A barometer, which is an inftrument genc-
liiUy known, 15, properly fpeaking, a fpecies of
fyphon, ABCD, PI. XII. Fig. x6. whofe leg AB
is filled with mercury, while the leg CD is full
of air. If we fuppofe the branch CD indefinitely
continued till it equals the height of our atmo-
fphere, we can readily conceive that the baro-
meter is, in reality, a fort of balan«e, in which

OF CHEMISTRY. 4^7

•

a columa of mercury (lands in equilibrium with
a column of air of the fiime weight. But it is
unnecefiary to prolongate; the branch CD to
fuch a height, as it is evident that the barome*
ter being immerfed in air, the column of mer*
cory AB will be equally in equilibrium with a
column of air of the fiune diameter, though the
leg CD be cut off at C, and the part CD be ta«
ken away altogether. ...

The medium height of mercury in equili-
brium with the weight of a column of air, from
the higheft part of the atmofphere to the furface
of the earth, is about twenty-eight ^>ench or
29.85 Englifh inches in the lower parts of the
city of Paris ; or, in other words, the air at the
furface of the earth at Paris is ufually prelTed
upon by a weight equal to that of a column of
mercury twenty-eight inches in height. I mull
be underftood in this way, in the feveral parts
of this publication, when talking of the different
gaffes ; as for inftance, when the cubical foot 9f
oxygen gas is faid to weigh 538.45 grs. under
^9.85 inches preffure. The height of this cq-
lumn of mercury, fupported by the preffure of
the air, diminiflies in proportion as we are ele-
vated above the furface of. the ; earth, or rather
above the level of the fea ;. becaufe the mercury
can only form an equilibrium with the column of
air which is above it, and is not in the fmallelt de-
gree afTeded by the air which is below its leve).

Cc4 Jul

£ L £ M £ N T J

In what ratio does the mercury in du bvo.
meter defcend in propation to its elevation ? or,
which is- the fame thing, according to what law
or ratio do the feveral ftrata of theatmolpheie
decreafe in denfity ? this queftton, Which hv
exercifed the ingenuity of natural philofopbers
during the laft century, is cmfiderably elucida-
ted by the following experiment.

If we take the glafs fyphon ABCDE, PI. XII.
Fig. 17. fhut at £, and open at A, end-introduce
a few drops of merely, fo as to intercept the
communication of air between the leg AB and
the leg BE, it is evident that the air contuned
in BCDE is prelled upooi in common with the
whole furrounding'uit,'hy a weight or column
of air equal to 29.85 inches of mercury. But,' if
wc pour 29.85 inches of mercury into the let

OF CHEMISTRY. 409

fpace from D to £, or exadly one quarter of
the fpace it occupied at the commencement of
the experiment. From thefe experiments^ which
may be infinitely varied, it has been deduced as
a general law of nature, which feems applicable
to all permanently elaftic fluids, that they dimi*
nifh in volume diredly in proportion to the
weights with which they are prefled ; or, in other
words, ** tbe volume pf all elajlic fluids is in tbe
^* inverfe ratio of the wfigbt by wbicb tbey are
** comprejid.*^

The ex^iments which have been made for
meafuring the heights of mountains by means
of the barometer, confirm the truth of thefe de-
dudions ; and even fuppofing them in fome
degree inaccurate, thefe differences are fo ex-
tremely (mall, that they may be reckoned as no-
thing in chemical experiments. When this law
of the compreffion of elaftic fluids is once well
underftood, it becomes eaflly applicable to the
corredioDS, neceflary in pneumato-chemical ex-
periments, upon the volume of gas, in relation to
its preflurCk Thefe corrections are of two kinds,
the one relative to the variations of the barome-
ter, and the other for the column of water or
mercury contained in the jars. I (hall endeavour
to explain thefe by examples, beginning with
the moft fimple cafe.

Suppofe that 100 cubical inches of oxygen
gas are obtained at inciies 54*5^ of tho thenno-

4«-

ELEMENTS

ineter, and at 33.37 indm of the btrometc^
it is required to know what Tolimie the 100
cufatcal inches of gas would occapy, under the
prediue of i^-^S inches, and what is the exad
weight of the too inchei of oxygen gas? Let
tbe unknown Tolom^ or the number of inches
this gas would occupy at 25^85 inches of the
huometer. be cxptefled hj x; and. fioce the
tqIu2x^ ue in the rnierfe ittio of thdr fuper-
iac-j-ztbcnt wei^ttiw *c b>ve the following ftate-
iT-cut - ICO cubical inchei is to x, ioTerfely aa
jir.3- ioohes of pnfluR is to 39.85 inches ; or
litnKlty Z9A$ : 30.37 : : 100 : x = iot.741 •^''
cubical inches, at 39.85 ladieB baranetrical pref-
lure ; th^ is to bj, the lune gas or aic whidi
at jc.^:; in>:hes of the harometer 'occupies too
(.-ubicii inches of volume, will occupy 101.741 _

OF CHEMISTRY.

4ti

niaft be in tbe dire£t ratio of tbe lame compref-
fioQ : Hence, fince loo cubical inches weigh
31.1023 grains, under the prelTare of 29.85 in-
ches, we have the following ftatement to deter-
mine the weight of 100 cubical inches of the
lame gas at 30.37 barometrical prefTure ; 29.85 :
31.^023 : : 30.37 : *, the unknown quantity.^
31.644.

Tbe following cafe is more complicated :
Suppofe the jar A^ Fl. XII. Fig. 18. to contain
a quantity of gas in Its upper part AGD, the
reft of the jar below CD being full of mercury,
and the whole Handing in the mercurial bafon
or refervoir GHIK, filled with mercury up to
EF, and that the difference between the furface
CD of the mercury in the jar, and EF, that in
the ciflem, is fix. inchee, while tbe barometer
ftands at 27.5 inches : It is evident from thefe
data, that the air contained in ACD is preffed
upon by the weight of the atmofphere, diminifli-
«d by the weight of the column of mercury CE,
or by 27.5-^=21.5 inches of barometrical pref-
fure. This air is therefore lefs comprcfled than
the atmofphere at the mean height of tbe ba-
rometer, and confequently occupies more fpace
than it would occupy at the mean preffure, the
difference being exadly proportional to the dif-
^icnce between tbe conipreffing weights. If,
then, upon mcuiuring the J'pace ACD, it is .
found to be 120 cubical inches, it mull be r
duq

ELEMENTS

Co tke Tobme which it would

OCCBfy

> wtaa picAue of 39.85 incha. This
^ ■ doae hgr Ae fiaUovin^ ftatnnent : 120 : :^ the
rafeae, : : 21.5 : 29.85 ntTcr^y ; ihis
gire* »='"^/= 86.43^ cuhicai inches.

la thefe cslcnlatkxs we may either rednce
, Kke height of the mcictirr ia the barometer, and
f Ac di2eraice of lerel in the jir and bafoo, to
I fincSt or to deCiinil fradions of the inch ; but I

I prefer the Ixcier. as it b more readily calcubted.
[ As, in tbele cyctauocs. which ftcgaentlT recur,
LSt b of great ule to have meam ot abbreriation,

I I bare giTco a Cable in the appendix for redu-
] ong lines and firadiom of lines into dccmol
PnadioD3 of the inch.

In expenments perfbnncd in the water appart.
\ tas^ we muA make (imilar conedioas 10 procure
I'jrigorouflT exad refulrs, bv talung into account,
aad makiDg allowance fnr the difference of height
of the water wilbin the jar abore the far^cc of
the water in the ciftcm. But, as the prefiUre of
the aimofpherc is exprefled io inches and lines of
the mercurial barometer, and, as homogeneous
quantities only can be calculated together, we
mud reduce the obferved inches and lines of wa-
ter into correfpondent height* of the mercury. I
have given a table in the appendix for this con-
Tcrfion, upon the foppofition thai mercury is
13.56S1 time? hearier than water.

sec:

OF CHEMISTRY. 4tS

S E C T. VL

O/Corre&ions relative to tbe Ikgrees ^f tU Tber-

tmmeter.

/

In . afcertatning : the weight of. gafles, befides
leducing them tp a mean of barometrical pref-
fiire, as direded in the preceding fedion^ we
muft likewife tedace them to a ftandard tber-
mametrical temperature; becaufet all elailic
fluids being expanded by heat, and condenfed
by c^ld, theor weight in any determinate volume
is thereby liable to.confiderable alterations. . As
the temperature 0^54.5? is a medium between
the. heat of fummer And the cpld of winter^be-r
ing the temperature oif fubterranepus places, aad
that which is moft eafily approached to at all
ieafons, I have chofcn that degree as a mean to
which I reduce air or gas in this ^ecies of cal-
culation.

Mr de Luc found that atmolpheric air was
increafed -^ part of its bulk, by ^ach degree
o^ a mercurial thermometer, divided i^to %i
degrees, between^ the freezing and bpibng
points; this gives. -f|- .part for each degree of

Reaumur^s

1

4^4

ELEMENTS

Reaumur's thennometer, vhich is divided ima
80 degrees between thefe two points ; or — i—
part for each degree of Fahrenheit's fcale, n-faich
is divided into 180 degrees between the fame
fixed points. The experiments of Mr Monge
leeni to make this dilatation lefs for hydrogen
gas, which he thinks is only dilated -^^ for
each degree of Reaumur, or -^^ for each of
Fahrenheit's degrees. We have not any exa<^
experiments hitherto publiflied relpeding the
ratio of dilatation of the other gafles ; hut, from
the trials which have been made, their dllata-
lioa feemsto differ little from that of atmo-
fpheric air. Hence I may take it for granted, till
farther experiments give us better information
upon this fubjed, that atmofpherical air is dila-
ted YT-5- P^rt, and hydrogen gas -^^ part for
each degree of Reaumur's thermometer, or that
atmofpheric air is dilated ~^ part, and hydro-
gen gas -^ part for each degree on the fcale of
Fahrenheit ; but, as there is (till great uncertain-
ty upon this point, we ought always to operate
in a temperature as near as pofTible to the itaod-
ard ot 54.5" ; by this means any errors in cor-
refting the weight or volume of gafles by redu-
cing them to the common ftandard, wiirbecQi
of little moment.

The calculation for this corredion Is.,

trcniely t3/y. Divide the obfervedvolbrhe'Sf

au-

OF CHEMISTRY.

4li

wr by no, for Reaumur^s fcale, or 472.5 for
that of Fahrenheit, and multiply the quotient by
the degree of temperature above or below 54.5*.
This corredion is negative when the aAual tem-
perature is above the ftandard, and pofitive when
below. By the ufe of logartthmetlc^I tables,
this calculation is much facilitated.

SECT. VII.

Example for calculating tbe CorreHtons relative t»
the variations of Prepare and Temperature.

In the jar A, PI. IV. Fig. 3. ftaiiding in. a
water apparatus, is contained 353 cubical inches
of air ^ the furface of the water within the jar at
EF is 4i- inches above the water in the cillem,
the barometer is at 27 inches 91 lines, and the
thermometer at 65.75". Having burnt a quan-
tity of phofphorus in the air, by which concrete
phofplioric acid is produced, the air after the
combuflioii occupies 295 cubical inches, the wa-
ter within the jar ftands 7 inches above that in

the

416

ELEMENTS

the cUlern. tbe barometeT b at 27 tncfaes 9J
lines, and the thermometer at 68". It is requi<
red from ihcfe data to detenninc the adual to-
lume of air, befcnr and afKr corobaftion, a
the qoaatitjr ;difbibed duiing tbe proccfs.

Cakvlation before Combu/Hon.

The air in the jar before comboftion was 353
cubical inches, but it was only under a barome-
trical preflure of 27 inches ^i- lines ; which, re-
duced to decimal fradions hj Tab. I. of the Ap-
pendix, gives 27.79167 inches ; and from this
wemuftdeduathediiFerenceof4i- inches of wa-
ter, which, by Tab. II. correfponds to 0.33166
inches of the barometer ; hence the real preflure
of the air in the jar is 27.46001. As the vo-
lume of elaftic fluids diminilhes in the inverfe
ratio of the compreffing weights, we have the
following ftatement, to reduce the 353 inches to
the volume the air would occupy at 28 inches
barometrical preflure.

353 : *,the unknown volume, : : 27.46001 : 't
Hence, * =2iliiZ^' = 346.192 cubical^
ches, which is the volume the fame quantity
■ ■ . of

OF CHEMISTRY.

417

«f air would hare occupied at 28 inches of the
barometer.

The 472.5th part of this correfted volume is
.73247, which, for the 11.25 degrees of tempe-
rature aboTC the ftandard, gires 8.24 cubical in-
ches ; and, as this corredion is fubtradive, the
real correded volume of the air before combuf-
tion is 337.952 inches.

Calculation after Combu/lton,

By a iimilar calculation upon the volume of
air after combuflion, we End its barometri-
cal preflure 27.77083 — 0.51593 = 27.25490.
Heilce, to have the volume of air under the
preflure of 28 inches, 295 : x '.: 27.77083 : 28
inverfely ; or * = 'ssX|7-i?49o _ 287.150. The
y(,72.5th part of this correded volume, is .61,
which, multiplied bj 13.5 degrees of tbermomei
trical difference, gives the fubtradive corredioQ
for temperature,- 8.335, leaving the adual coc-
reded volume of aii after combuftioo 278.925
inches. ■■

I

418

ELEMENTS

Rffult.

The conreded Tolume before combuf-

(loa, - - - ssTi

Ditto rcmainiQg after combnOioo, • 278.915

Volume abfotbed during combufUon,

SECT. VIIL

MtlboJ of iU:rrmiai^f tbe Abfthtt GravUj ef tbt

different Gajfet.

Tiike a large balloon A, PL V. Fig. iOl
pable of holding 1 7 or iS pints, or aboat half^
cubical foot, having the bnfs cap bcJe ftroogly
■«mtnipd to its neck, and to which tbe tube and
'ftop-cock / j- i j fixed by a tight fcrew. This ^»-
•jnntu* is conn^ded by the double fcrew rcpre-
fnted feparateir at Fig. i :. to tbe jar BCD,
•i\g, 10. wKch muQ be fome pints bu^r ta di-
mcnSom than the balloon. Thb jar » open K
top, and is furnifhcd witfa tbe brafs cap h i, and
tfic fiop-cock / m. One of thefe flop-codes b
reprefcmed leparately at Fig- li.

OF CHEMISTRY.

419

I

I

I

We firfl determine the exad capacity ot the
balloon by filling it with water, and weighing it
both full and empty. When emptied of water,
it is dried with a cloth introduced through its
neck d e, and the lall remains of moiftiirc are
removed by exhaufting it once or twice in an
air-pump.

When the weight of any gas is to he alccr-
tained, this apparatus is uftd as follows : Fix
the balloon A to the plate of an air pump, by
meansof thefcrewof the llop-cock/^, which is
left open ; the balloon is to be exhaufted as com-
pletely as poffible, oblerving carefuUy the de-
gree of exhauftion by means of the barometer
attached to the air-pump. When the vacuum is
formed, the flop-cock/f is ihut, and the weight
of the balloon determined with the moU fcru-
pulous exadlitude. It is then fixed to the jar
BCD, which we liippofe placed in water jn
the ihelf of the pneumato-chemical apparatus
Fig. 1. ; the jar is to be filled with the gas wc
mean to weigh, and then, by opening thi; iiop-
cocks/j and i m, the gas afccnds into the bal-
loon, whilft the water of the ciftern rifes at the
fame time into the jar. To avi;id very trouble-
fome corrcdions, it is neceflary, during this livlt
part of the operation, to fink the jar in tlie cif-
tern till the furfaces of the water within and
without the jar exactly correfpoml. The ftop-
cocks are sgain fliut, and the balloon, being un-
D d 2 fere wed

»

4»0

ELEMENTS

fcrewed from its coonedion wilb the jar, ]
be carefally weighed ; the difference between
thi$ weight atul that of the exbaufled balloon h
the precifc weight of the air or gat contaiaed in
the balloon. Multiply this weight by 1728, the
number of cubical inches in 3 cabical foot, and
divide the produift by the number of cubical
inches contained in the balloon, the quotient is
the weight of a cubical foot of the gas or air
fubmiited to experimcat,

Exad account mull be kept of the barometri-
cal height and the temperature of the thermome-
ter during the above experiment ; and from thefe
the relulting weight of a cubical foot is cafily
corrected to the tlandards of 28 inches prcffure,
and 54.5° temperature, as direQed in the prece-
ding fedlion. The finall portion of air remain-
ing in the balloon after forming the vacuum,
rouft likewife be attended to, and this is eafily
determined by the barometer attached to the air-
pump. If that barometer, for inftance, remains
at the hundredth part of the height it Hood at
before the vacuum was formed, we conclude that
one hundredth part of the air originally contain-
ed remains in the balloon, and confequently that
only -fS^ of gas was introduced from the jar iii>
to the balloon.

OF CHiEMISTRY. 421

CHAP. III.

Dejcription of the Cohrimeter^ or Apparatus for

meajkring Caloric^

THE calorimeter, or ajyparatus for tneafuring
the relative quantities of heat contained in
bodies, was defcribed by Mr de la Place and
me in the Memoirs of the Acadiemy for 1780,
p. 355. and from that Effay the materials of this
chapter are extr^fted.

If, after havin^cooled any body to the freez-
ing point, it be expofed in an atmofphere of
88.25 **, the body will gradually become heated,
from the furface inwards, till at laft it acquire
the fame temperature with the furrounding air.
Bat, if a piece of ice be placed in the fame fitua-
tlon, the circumflances are quite different ; it
does iiot approach in the fmalleft degree towards
the temperature of the circumambient air, but
remains conftantly at 32*, or the temperature of
melting ice, till the laft portion of ice be com-
pletely melted.

This phenomenon is readily explained ; as,
to melt ice, or reduce it to watdr, it requires to
be combined with a certain portion of caloric,

D d 3 the

:ELEB«Ei3»TS

the whole caloric attraded from the furroundiiy
bodies, is arrefted or fixed at the furfoce or ex-
ternal layer of ice nhich itif employed to dl£>
foire, and combines with it td'fbrm water ; the .
next quantity of caloric combines with the fe-
cond layer to diflblve It into water, and fo.on
fucceflively till the whole 'ice be diflblved, or
converted into water, by combination with calo-
ric ; the very laft atom flill remaining at its for-
mer temperature, becaufe the caloric could ob-)
ver penetrate fo far, while any intermediate ice
remained to melt, or to combine with.

Upon tbefepiiiteij^bs, if we- c«K:eiTe a hol-
low fphere of ice at the temperature of 3a*
placed ill an atmofphere oF 54.5", and contain-
ing a Jubilance at any degrrf of temperature

OF CHEMISTRY. 423

of the water will be exadlj proportional to the
quantity of caloric loft by the body, in:pa(fing
from its original temperature to that of melting
ice ; for it is evident that a double quantity of
caloric would have melted Iw ice. the /qubptity
of ice. Hence the quantity of ice melted i% (i
very exadt meafure of the proportion^ quantity
of caloric employed to produce that effed,. an4
confequently of the quantity loft by the only fubf^
ftance that could poiBbly h^ve fupplied iL:::.:. j

I have made this fuppofition, of what .wc>iHii
take place in a hollow fphere of ice, for the pur^
pofe of more readily explaining the method a&d
in this fpecies of experiment, which wasi iirft
conceived by Mr de la Place. It would be. dif^.
fiqult to procure fuch fpheres of ice, and incon-^
venient to make ufe of them when got ; but, by
means of the following apparatus, webayerq^
medied that defe(^. I acknowledge the namie^
of Calorimeter, which I have given it^ as derii/ed
partly from Greek and partly firom Latin; is ia
fome degree open to criticifm ; but|: m^ loa^ter^
of fcience, a flight deviation from ftri£l etymolo.*
gy, for the fake of giving diftindnefs of ideta^. 19,
excufable j and I could not deriyetbe name; en-
tirely from Greek without approaching too near
to the names of known inftruments employed for
other purpofes.

The calorimeter is reprefented in PI. V|» . It is
fliown in perfpeclive at Fig. i. and its interior

D d 4 ftrudure

4*4

: L £ BCElfNTS

ftruaure is engraved at Figi z. and 3. ; thsCAk
mer being a horizmitM* iiA ^k Utter a perpen*
dicular feOion. ItSTd^acity or cavity is di-
vided into.three part^'Whicli, for better difUao^
tioA> I &aU name the interior^ middle, and ex-
ternal cavities. TbeiitterM»caVit7////,Fig.4;
into .which the. fnbftancc^.fubmitted to experi-
ment'are put, is compofed oft grating or cage
ef itod wire, fuppon^d by (everal iron bars ; io
opening or mouth- XIM^ it coverd 1^ the lid
^0»- which ii compo&dof the fame materials.
The nnddle cavity bibb, Fig. a. and 3* is iiw
Seeded to contain the ice which furroonds th»
interior-caTity, and which is intend^ -to be
melted- by the citric of the fubftHicek emptoyecl'
in the experiment. - The ict 'is fupported by

OF CHEMIStRY.

425

Vity from the beat of the furroundlng air, and
the water produced fvom it is carried'ofT through
the pipe S T, wfakfa ihuts by ineaiH of the ftop-
cock r. The whole machine is corered bj the
lid F F, Pig. 7. which is made of tin, and paint-
ed with oil colour, to prevent ruil.

When this machiae is employed, the middle
cavity hbbb. Fig. 2. and 3. the lid G H, Fig. 4.
of the interior cavity, the external cavity aaaUy
Fig. a. and 3. and the general lid F F, Fig. 7.
are all filled with pounded ice, well rammed,
fo that no void fpaces remain, and the ice of the
widdle cavity is allowed to drain. The machine
is then opened, and the ftibllance fabmitted to
experiment being placed in the interior cavity,
it is inftantly clofed. After waiting till the in-
cluded body is completely cooled to the freez-
ing point, and the whole melted ice has drained,
from the middle cavity, the water collefted in
the veffel F, Fig. i. is accarately weighed.
The weight of the water produced during the
experiment is an exad raeafure of the caloric
difengaged during the cooling of the included
body, as this fubflance is evidently in a limilar
iituation with the one formerly mentioned as in-
cluded in a hollow fphere of ice. The -whole ca-
loric difengaged from the included body is Hop-
ped by the ice in the iniddle cavity, :ind that
ice is preferved from being affcfied by a
heat by means of the ice contftiDj

426

E L EM E N T S

ral lid, Fig. 7. and in the extenial cavity. Hrp^
rimentsof this kind generaljljlaft from fifteen to
twenty hours, but they are fometimes accele-
rated by coveting up the fubftance in the interior
carity with well drained ice, which haftens kt
cooling.

The fubftances to be operated upon are placed
in the thin iron bucket. Fig. 8. the cover of which
has an opening fitted with a cork, into which a
fmall thermometer is fixed. When we ufe acids,'
or other fluids capable of injuring the metal of
the inftruments, they are contained in the ma-
trafs, Fig. 10. which has a fimilar thermomctqr
in a cork fitted to its mouth, and which ftaods
in the interior cavity upon the fmall cylindrical
fupport R S, Fig. 10.

OF CHEMISTRY. 427

the air be under t^e degree of freezing, it might
cool the ice contained in the middle cavity, by
caufing the ice in the external cavity to fall, in
the firft place, below 32^. It is therefore eifen-
tial that this experiment be carried on in a tem-
perature fomcwhat above freezing : Hence, in
time of froft, the calorimeter muftbe kept in an
apartment carefully heated. It is likewife necef-
fary that the ice employed be not under 32'', for
which purpofe it muft be pounded, and fpread
•out thin for fome time, in a place where the
temperature is higher.

The ice of the interior cavity always retains a
certain quantity of water adhering to its furface,
which may be fuppofed to belong to the refult of
the experiment ; but as, at the beginning of each
experiment, the ice is already faturated with as
much water as it can contain, if any of the wa-
ter produced by the caloric ihould remain attach-
ed to the ice, it is evident, that very nearly an
equal quantity of what adhered to it before the
experiment muft have run down into the veflel
F in its ftead ; for the. inner furface of the ice
in the middle cavity is very little changed du-
ring the experiment.

By any contrivance that could be devifed, we
could not prevent the accefs of the external air
into the interior cavity, when the atmofphere
was at 52 *" or 54**. The air cgnfined in thei.C
vity being in that cafe fpccifically heavier t]

4«8

£ L E ME NTS

the external air, elb^Ks dowitwtitU thmngklfee
inpe xj. Fig. 3, and it icplaoed hy the wtiJiiHi
external air.'wliichr givkigmt iti caloric iiv4e
ice, become* twaTier, md fiiAi in iu tnra' ; - Aife
a current of atf is formed 4magl^ the mniltihii,
which is the more rapid ia pM^Mition ai tb« ^M-
ternal ur exceeds'tbe intenial mtenperttoM
This current of warm air moft' melt a past .«f
the ice, and injure die accoracj of the expsti-
raent. We nay, ia a great degfee, guard *•
gainft this fource of erm- hy keeping the ftop
cock u continually lhut» but it is h^txxx ta openni
only when the tempeittufe of the external a^-
does notex«eed-39*,'orat tBoft 41*, fbiweha«e
obferyed, that, m thit'cafe^ the mehingof tbe
interior ice by the atmofpheric air is perfeAly in-

OF CHEMISTRY.

4»9

It is extremely eafy, with this apparatus, to
determine the phenomena which occur in ope-
rations where caloric is either difengaged or ah-
Ibrbed. If we wifh, for inftance, to afcertain
the quantity of caloric which is difengaged from
a folid body in coc^ng a certain number of de-
grees ; let its temperature be firft raifcd to 212*^,
it is then placed in the interior cavity////.
Fig. 2. and 3. of the calorimeter, and allowed
to remain till we are certain that its tempera-
ture is reduced to 32" ; the water produced by
melting the ice during its cooling is colleded,
and carefully weighed ; apd this weight, divided
by the volume of the body fubmitted to experi-
ment, and multiplied into the degrees of tempe-
rature which it had above 31° at the commence-
ment of the experiment, gives the proportion
of what the £nglill| philofophers call fpecific
heat.

Fluids are contained in proper veflels, whofe
fpecific heat has been previoufly ascertained, and
are operated upon in the machine in the fame
manner as dire^ed for folids, taking care to de-
dud, from the quantity of water melted during
the experiment, the proportion which belongs to
the fpecific heat of the containing vefleL

If the quantity of caloric difengaged during
the combination of different fubftances is to be
determined, tfaefe fubftances aret^
ly reduced tfi the

Z 1 Z M E N T 3

■-■:: -jre iirrz-z-zcd with pounded
- -: > :'-«:: ;r be zaiie in the inoet
, ^:rsz<ziz, ir. i proper velTel like-
•.-- ;i- ; i:&I ibsj are kept inclofed
-.■~::ur; .-f the combirLiiion has re-
. -■; i.;-rT<« : The quantity of wa-
- 1 iiii.'-iricf the caloric dilenga-

■■ V the »:Uur.:::v ^-f caloric dtleu-

■ : .■:rr.b»;:uor„ ard during animal

:■; ^vir.^taiuble b^-iiiei are burnt, ot

> --.-; ~.iCi: ro brearbe, in the inte-

. --.-i. the witer produced is carefully

0::.r.ci-ni£S which reGll the efTcfls

:;:v;".y well, are well adapted for this

:. A* the continual renewal of air

OF CHEMISTRY.

431

becaufe the caloric difengaged from this air is
part of the produA of the experiment.

It is fomewhat more difficult to determine the
fpecific caloric contained in the different gafles,
on account of their fmall degree of deniity ; for,
if they are only placed in the calorimeter in
veflets like other fluids, the quantity of ice melt-
ed is fo fmall^ that the refult of the experiment
becomes at heft very uncertain. For this fpecies
of experiment we have contrived to make the
air pa& through two metallic worms, or fpiral
tubes ; one of thefc, through which the air paf-
fes, and becomes heated in its way to the calo-
rimeter, is contained in a veflel full of boiling
water, and the other, through which the air cir-
culates within the calorimeter to difengage its
caloric, is placed in the interior cavity, ffff, of
that machine. By means of a fmall thermome-
ter placed at one end of the fecond worm, the
temperature of the air, as it enters the calori-
meter, is determined, and its temperature in
getting out of the interior cavity is found by an-
other thermometer placed at the other end of
the worm. '&j this contrivance we are enabled
to afcertain the quantity of ice melted by deter-
minate quantities of air or gas, while loling a
certain number of degrees of temperature, and,
confequently, to determine their feveral degrees
(»f Ipecific caloric. The lame apparatus, with
feme particular precautions, may be employed

43»

£L£ M£ NTS

to afcertain the quantity of caloric diieog^ni
by the condeniatioa of the vapours of di&icat
liquids.

The various experiments which may be made
with the calocinieter do not afford abfolute con-
cluGons, but onljr give as the meafure of Tela>
live quantities ; we have tbcrcfoFe to fix a uoil;
or ftandard point, from whence to form a ibale
of the feveral refulta. The quantity of caloric
iKcellary to melt n pgund of ice has been choiea
us this unit i and, 8» it lequires a pound of water
of the temperature. <tf 167" to melt a pound of
icCf the quantity of caloiic exprefled by our unit
or ftandard point is what raifes a pound of wa-
ter froDi 32* to 167°. When this unit is once
determined, we have only to exprefs the quan*

OF CHEMISTRY. 433

pounds of ice were melted. Hence, the caloric
^ifengaged from the iron by cooling lys-S"" ha->
iring melted 1.109795 pounds of ice, How much
would have been melted by cooling 135* ? This
queftion gives the following ftatement in dired
proportion, 175.5 : 1.109795 : : 135 : a:r:o.8S384.
Dividing this quantity by th«^ weight of the
whole iron employed, vix. 770703 19, the quo-
tient 0.1109 ^^ the quantify of ice which would
have been melted by one pound of iron while
cooling through 135 degrees of temperature.

Fluid fubftance$, fuch as fulphUric and nitric
acids, &c. are contained in a matrafs. Pi. VI.
Fig. 9. having a thermometer adapted to the
cork^ with its bulb immerfed in the liquid. The
matrafs is placed in a bath of boiling water, and
when, from the thermometer, we judge the liquid
is raifed to a proper temperature, the matrats is
placed in the calorimeter. The calculation of the
produds, to determine the fpecific caloric of thefe
fluids, is m^de as above diredied, taking care to
dedud from the water obtained the quantity
which would have been produced by the matrafs
alone, which mud be afcertaiqed by a previous
experiment. The table of the refults obtained by
thefe experiments is omitted, becaufe not yet fuf*
ficiently complete, diflferent circumflances having
occafioned the feries to be interrupted ; it is not,
hbwever, loft fight of ; and we are lefs or more
employed upon the fubjeft every winter.

Ee CHAP,

ELEMENTS

CHAP. IV.

^ Mnbanical Operati nr for the l^m.
Bodies.

SECT. I.

Of Tnturathe, Levijatisn, and Puherlaatn

TB£S£ are, properly fpeaking, only pn
minary inechanicat operations for dividirg
and ftparating the particles of bodies, and redo-
piiig them into very fine powder. Thefe ope-
mions can never reduce fubnunces into their
primary, or elementary and ultiinate particlo
they do not even deflroy the aggregation of 1
dies ; for every particle, after the mod accui
trituration, forms a fmal) whole, refembling tte
original maf« from which it was divided- The
teal chemical operations, on the contrary, fuch
as folution, defiiny the aggregation of bodies,
and feparate their conrtitucnt and integrant par-
ticlcs from each other.

J

OF CHEMISTRY. 435

Brittle fubftances are reduced to powder by
means of peftles and mortars. Thefe are of
brafs or iron, PL L Fig. i. ; of marble or gra-
nite. Fig. 2. ; of ligmim vitae, Fig. 3. ; of glafs,
Fig^4. ; of agate. Fig. 5. ; or of porcelain, Fig. 6.
The peftles for each of thefe are reprefented
in^ the plate, immediately below the mortars
to which they refpedively belong, and are made
of hammered iron or hra(s, of wood, glafs^
porcelain, marble, granite, or agate, according
to the nature of the fubftances they are in-
tended to triturate. In every laboratory, it is
requifite to hare an aflbrtment of thefe uten--
fiisy of various fizes and kinds : Thofe of por-»
celain and glafs can only be ufed for rubbing
fubftances to powder, by a dexterous ufe of
the peftie round the fides of the mortar, as it
would be eafily broken by reiterated blows of
the peflle.

The bottom of xtiortars ought to be made iit
form of a hollow fphere, and their fides fhould
have fuch a degree* ofiiocUoation as to maka
the fubftances they contain fall back to the bot-
tom when the peftie is lifted, bat not (o perpen-
dicular as to colled them too mucli together,
otherwife too large a quantity would get below
the peftie, and prevent its operattoo. ' Fotr this
reafon, likewife, too large a quantity of the fuU*
ftance to be powdered ought not to' be put into
the mortar at one time ; and we muft from

E e 2 time

ELEMENTS

fiBM to time get rid of the particle; already ic-
daced to ponder, bj means of Seres to be af»
terward; dricnbed.

The mofl ufual method of lerigation is hgr
means of a flat table ABCD, PL I. Fig. ;. made
of porphyry, or fome other ftooe of fimjlar hard-
nefs; on thii the fubftaoce to be reduced Eo
powder is fpread, and is then biiiifed and mlh
bed bv a muller M, of the f^one hard materials.
the bouom of which is made a fmall portion of
a large fpbcre ; and, as the muller tends conti-
nually to driTc the fubftances towards the fides
of the table, a thin flexible knite, or fpatula cif
iron, horn, wood, or ivory, ii ufed for bringing
them bact to the middle of the ftonc.

In large works, this operation is performed
by means of large rollers of. hard ilonr, which
turn upon each other, either horizontally, in the
way of com-mills, or by one vertical rollet
turning upon a flat-ftone. In the above opera-
tions, it is often requiiite to moineu the fub-
tlaocet a little, to prevent the fine powder from
Hying off.

There are many bodies which cannot be re-
duced to powder by any of the foregoing me-
thods ; fuch are fibrous fubfiances, as woods,
fuch fubftaoces as are tough and elaflic, as the
horns of animals, claflic gum, fee. and the mal-
leable metals, which flatten under the pefUc,
jollead of being reduced to powder. For rcda-

^2jj

OF CHEMISTRY. 437

tiiig the woods to powder, rafps, as in PI. L
Fig. 8. are employed ; files of a finer kind are
ufed for horn ; and ftill finer, PL I. Fig. 9. and
lo. for metals.

Some of the metals, though not brittle enough
to powder under the peftle, are too foft to be
filed, as they clog the file, and prevent its opera-
tion. Zinc is one of thefe, but it may be pow-
dered when hot| in a heated iron mortar, or it
may be rendered brittle^ by alloying it with a
fmall quantity of mercury. One or other of thefe
methods is ufed by fire-work makers for produ«
cing a blue flame by means of zinc. Metals may
be reduced into grains, by pouring them when .
melted into water, which method ferves very
well when they are not wanted in fine powder.

Fruits, potatoes, &c. of a pulpy and fibrous
nature, may be reduced to pulp by means of the
grater, PI. I. Fig. 11.

The choice of the different fubf(ances of which
thefe inftruments are made is a matter of impor-
tance ; brafs or copper are unfit for operatjons
upon fubftances to be ufed as food or in pharma-
cy ; and marble or metallic inftruments ^lult
not be ufed for acid fubftances ; hence mortars
of very hard wood, and thofe of porcelain, gra-
nite, or glafs, are of great utility in inany ope-
rations.

Eea SECT.

•

438

ELEMENTS

SECT IF.

Of Sifting and Wajbing Powdered Subjlancej.

None of the mechanical operations, employed
for reducing bodies to powder, is capable of pro-
ducing it of an equal degree of finenefs through-
out ; the powder obtained by the longed and
mod accurate trituration being ftill an afTem-
blage of particles of various fizes. The coarfer
of thefe are removed, fo as only to leave the
finer and more homogeneous particles, by means
of fieves, PI. I. Fig. 12, 13, 14, 15. of different
finenefles, adapted to the particular purpofes
they are intended for ; all the powdered matter
■which is larger than the inlerftices of the fieve
remains behind, and is again fubmittcd to the
peftle, while the finer paffes through. The Gevc
Fig. 12. is made of hair-cloth, or of filk-gauxe ;
and the one reprefented Fig. 1^. is of parch>
raent pierced with round holes of a proper file ;
ihis latter is employed in the manufaiflure of
gun-powder. When very fubtile or valuable
materi lis are to be fifted, which are eafily
difperfed, or when the finer parts of the powder
may be hurtful, a compound lieve, Fig. 15. is
made ufe 0^ which confifts of the fievc ABCD,
with

wrt^l

with a lid £F, tud itceiTer OH ; thefe three
parts are reprefented ai joined together for ufe^
Fig. 14.

There is a method of procuring potrders of
an uniform finenefs» confiderably more accit«
rate than the fieve ; but it can only be ufed
with fucb fubftances as are not adled upon by
water. The powdered fubftance is mixed and
agitated with water. Or edy Other convenient
fluid ; the liquor is allowed to fettle for a few
moments, and is then decanted off; the coarfefl
powder remains at the bottom of the vefTel, and
the finer pafles over with the liquid. By re-
peated decantattons in this manner, various fe-
diments are Obtained of different degrees of
finenefs ; the laft fedimrm^ or that f?hich re-
mains longeft fiifpended in the liqiKlr, being the
fined. This procefs may iikewife be ufed with
advantage for feparaliDg fubftances of different
degrees of fpecific gravity, though of the fame
finenefs ; this laft ii chiefly employed in mfning^
for feparating the heavier metallic ores ftom tht
lighter earthy matceis with wbkh they aro mix-
ed.

In chemical laboratories, pans aod jugl of glafs
or eatthen-ware, are employed for this operation ;
fometimes for decanting the liquof without di^
turbing ^e fediment, the glafs fyphon aBCHI^
PL IL l^tgi 11 At ufed, which may be fupporled
. bjrJRdm of the perforated board DE, at the

£ f 4 proper

■/

440 ELEMENTS

proper depth in the veflel FG, to dtaw off aH
the liquor required into the receiver LM. The
principles and application of this ufeful inftni-
ment arc fo well known, u to need no ex{ilaiu>

tion.

SECT. in.

Of Fiitration.

A filtre is a fpecies of rery 6ne fieve, which it
permeable to the particles of fluids, but through
which the particles of the fineft powdered foUdi

t)F CHEMtS'TRY. 44!

through this fubftance, no folid body, however
firiely it be {>owdered, can penetrate, and fluids
percolate through it with the greateft readinefs.
As paper breaks eaiily when wet, various me-
diods of fupporting it are ufed according to cir-
cumftances. When a large quantity of fluid is
to be filtrated, the paper is fupported by the
frame of wood, PL II. Fig. 3. ABGD, having a
piece of coarfe cloth ftretched over it, by means
of iron-hooks* This cloth mud be well cleaned
each time it is ufed, or even new cloth mud be
employed, if there is reafon to fufped its being
impregnated with any thing which can injure the
fubfequent operations. In ordinary operations,
where moderate quantities of fluid are to be fil-
trated, different kinds of glafs funnels are ufed
for fupporting the paper, as reprefented PL 11.
Fig. 5, 6. and 7. When feveral filtrations mud
be carried on at once, the board or Ihelf AB,

«

Fig. 9. fupported upon ftands C and D, and
' pierced with round holes, is very convenient for
containing the funnels.

Some liquors are fo thick and clammy, as
not to be able to penetrate through paper with-
out fome previous preparation, fuch as clarifica-
tion by means of white of eggs, which, being
mixed with the liquor, coagulates when brought
to boil, and, entangling the greater part of the
impurities of the liquor, rifes with them to the
furface in the ftate of fcum. Spiritous liquors

mav

442

ELEMENTS

may be clarified in the fame manner bj means
of ifinglafs diflblved in water, which coagulates
by the adion of the alkohol without the affift-
ance of heat.

As moll of the acids are produced by diitil-
lation, and are confequently clear, we have rarely
any occation to filtrate them ; but if, at any time,
concentrated acids require this operation, it is im-
poffible to employ paper, which would be corrod-
ed and deftroyed by the acid. For this parpofe*
pounded glafs, or rather quartz or rock-cryflal,
broke in pieces, and grofsly powdered, anfwers
very well ■■, a few of the larger pieces are put in
the neck of the funnel, thele are covered with
the fmaller pieces, the finer powder is placed over
all. and the acid is poured on at top. For the

OF CHEMISTRY. 443

diSufed through liquors. Thefe are allowed to
fettle in conical veffels, ABCDE, PI. II. Fig. 10.
the diflrufed matters gradually lublide, and the
clear fluid is gently poured oflf. If the fediment
be extremely light, and apt to mix again with the
fluid by the flighted motion, the fyphon, Fig.ii.
is ufed, inftead of decantation, for drawing off
the clear fluid.

In experiments, where the weight of the pre*
cipicate mufl be rigoroufly ascertained, decanta-
tion is preferable to filtration, providing the pre-
cipitate be feveral times wafhed in a confider-
able proportion of water. The weight of the
precipitate may indeed be afcertained, by care-
fully weighing the filtre before and after the
(^ration ; but, when the quantity of precipi*
tate is fmall, th^ different proportions of moi-
fture retained by the paper, in a greater or lefler
degree of e9.ficcation, may prove a material
fource of error, which ought carefully to be
guarded againft.

CHAP.

£ L £ M £ N T !

CHAP. V.

Of Chemical Cleans for feparatiiig the PartUkj of
Biiiafnm each other, vattbout DecompefituM,
and far uniting them again.

IHare alreadv Ihcwn that there are two me-
thoii of dividing the particles of bodies, the
mftbanical and chewucal. The former only fe-
parates a foltd nuls into a great number of
linaUer mafles -, and for thefe parpofes various
ipecies of forces are emploved, according to cir-
cuinftanc«, fuch as the ftrength of man or of

OF CHEMISTRY. 443

to be a neutral fait. In this Chapter, I mean to
give examples of this kind of divifidn of bodies,
to which I (hall add fome account of the relative
operations.

SECT. I.

Of the Solution of Salts.

In chemical language, the terms oi folution
and dijfolution have long been confounded, and
have very improperly been indifcriminately em-
ployed for expreffing both the divifion of the
particles of a fait in a fluid, fuch as water, and
the divifion of a metal in an acid. A few re-
fledlions upon the effeds of thefe two opera-
tions will fuffice to (how that they ought not
to be confounded together. In the folution of
falts, the faline particles are only feparated from
each other, while neither the fait nor the water
are at all decompofed ; for we are able to recover
both the one and the other in the fame quantity
as before the operation. The fame thing takes
place in the folution of refins in alkohoL Du-
ring metallic di(rolutions, on the contrary, a
decompofition, either of the acid, or of the wa-
ter which dilutes it, always takes place ; the
metal combines with oxygen, and is changed

into

r^

4^6 ELEMENTS

into an oxyd, and a gafleous ftibftance is
gtgcd } To that in reality none of the AibfEao-
lcs employed remain, after the operation, in the
I'iimc ilate they were in before. This article is
cntirdy confined to the confideration of folu-
tioD.

To underlland properly what takes place du-
ring the folution of falts, it is neccflary to know,
that, in mod of thefe operations, two diftin^
cfFefls are complicated together, viz. folution by
water, and folution by caloric ; and, as the ex-
planation of nioft of the phenomena of folutioo
depends upon the diftinftion of thefe two cir-
(.umilnnces, I Hiall enlarge a little upon their oa*
ture.

Nitrat of potafli, ufually cnlled nitre or falt-
petre, contains very little water of cryftalliza-
tion, perhaps even none at all ; yet this fait li-
quifies in a degree of heat very little fuperior to
that of boiling water. This liquifadion caonot
therefore be produced by means of the vrnter of
«'tyftaili2ation,.but in confequencc of the fait be-
■iaijTtry fufible in its nature, and from its paffing
toon the folid to the liquid ftate of aggregation,
^nbut a little raifed above the temperature of
c vater. AU falts are in j|ii|tsanner fuf-
bat in
lSoicc

OF CHEMISTRY. 447

as fulphat of potaih, or of lime, &c, require the
ftrongeft fires we are capable of producing. This
liquifaSion of falts by caloric produces exadly
the fame phenomena with the melting of ice ; it
is accompliftied in each fait by a determinate de*
gree of heat, which remains invariably the fame
during the whole time of the liquifaO:ion. Ca«
loric is employed, and becomes fixed during the
melting of the fait, and is, on the contrary, dif-
engaged when the fait coagulates. Thefe are
general phenomena, which univerfally occur du-
ring the paffage of every fpecies of fubftance from
the folid to the fluid ftate of aggregation, and
from fluid to folid.

Thefe phenomena, arifing from folution by
caloric, are always lefs or more conjoined with
thofe which take place during folutions in water.
We cannot pour water upon a fait, on purpofe
to difiblve it, without employing a compound
folvent, both water and caloric ; hence we may
diftinguifli feveral different cafes of folution, ac-
cording to the nature and mode of exiftence of
each fait. If, for inftance, a fait be difficultly
foluble in water, and readily fo by caloric, it
evidently follows, that this fait will be fcantily
foluble in cold water, and coofiderably in hot
water ; fach is nitrat of potbfh, and more efpe*
cially oxygenated muriat of potaih. If another
fait be little foluble both in water and caloric,
he difference of its folubiiity in cold and wann

water

448

ELEMENTS

wnter will be very inconfiderable ; faIphatr--4
lime is of this kind. From thefe confideratiom^
it follows, that there is a neceflary relation be-
tween the following circumftances ; the folubili-
ty of a fait in cold water, its folubility in boii-
iiig water, and the degree of temperature at
which the fame fait liquifies by caloric, unafliRcd
by water ; and that the difference of folubility
in hot and cold water is fo much greater in pro-
portion to its ready folution in caloric, or in pro-
portion to itsfufceptibility of liquifying in a low
degree of temperature.

The above is a general view of folution ; but,
for want of particular fads, and fufficiemly ex-
ad experiments, it is (till nothing more than an
approximation towards a particular theory. The
lucans of completing this part of chemical fcience
is cutremely fimple ; we have only to afccr-
tain how much of each fait is diffolved by a cer-
tain quantity of water at different degrees of
temperature ; and as, by the experiments pu-
blifhed by Mr de la Place and me, the quantity
of caloric contained in a pound of water at each
degree of the thermometer is accurately known,
it will be very cafy to determine, by fimple ex-
periments, the proportion of water and caloric
required for folution by each fall, what quanti-
ty of caloric is abforbed by tach at the moment
of liquifaflion, and how much is dir:ngaged at
k ^e moment of cryffalUzation. Hence the rcafoa

OF CHEMISTRY.

why falts are more rapidly foluble in hot than
in cold water is perfedtly evident. In all folu-
tions of falts caloric is employed ; when that is
furnilhed inter mediately from the furrounding
bodies, it can only arrive flowly to the fait i
whereas this is greatly accelerated when the re-
quiGte caloric exifts ready combined with the
water of folution.

In general, the fpecific gravity of water is ang-
Hiented by holding falts in folution; but there
are fome exceptions to the rule. Some time
hence, the quantities of radical, of oxygen, and
of bafe, which conftitute each neutral fait, the
quantity of water and caloric neceffary for folu-
tion. the increafed fpecific gravity communicated
to water, and the figure of the elementary parti-
cles of the cryftals, will all be accurately known.
From thefe all the circumftances and phenomena
of cryftallization will be explained, and by thefe
means this part of cheraiHry will be completed.
Mr Seguin has formed the plan of a thorough
inveftigation of this kind, which he is extremely
capable of executing.

The folution of falts in water requires no par-
ticular apparatus; fmall glafs phials of diiferent
fixes, PL II. Fig. i6. and 17. pans of earthen-
ware, A, Fig. 1. and 2. long-necked matrafles.
Fig. 14. and pans or bafons of copper or of fil-
ver, Fig. 13. and 15. anfwer very well for thefe
operations,

F f SECT.

I

ELEMENTS

SECT. n.
Of Lixiviation.

This is an operation ufed in cheniiftry and
manufaQures for feparating fubflances which are
folubte in water from fuch as are infoluble. The
large vat or tub, PI, II. Fig. iz. having a hole
D near its bottom, containing a wonden-fpigoc
anJ fofiet, or metallic ftop-cock D E, is generally
ufed fnr this pqrpofe. A thin ftratum of ftraw
h placed at the bottom of the tub ; over this,
thf fublUnce to be lixiviated is laid and covered
by a cluth. then hot or cold water, ac, ording to
thi degree of fohibility of the falinc matter, is
poured on. When the water is fuppofed to have
difTolved all the laline parts, it is let off by the
ftop-cock ; and, as foine of the water charged
with fait necelfarily adheres to iheflraw and in-
foluble matters, fcveral frefh quantities of water
are poured on. 'Ihe ftraw ferves to fecure 9,
proper pafliige for the water, and may be com-
pared to the ftraws or glafs roads ufed in filtrat-
ing, to keep the paper from touching the fides
of the funnel. The cloth which is laid over the
itiattcr!t under lixiviation prevents the water from
making:

OF CHEMISTRY. 451

making a hollow in thefe fubftances where it is
poured on, through which it might efcape with-
out ading upon the whole mafs. .

This operation is lefs or more imitated in che-
mical experiments ; but as in thefe, efpecially
with analytical views,, greater exadtnefs is re-
quired, particular precautions muft be employed,
fo as hot to leave any faline or foluble part in the
refiduum. .More wat^r muft bf^ ctraployed than
in ordinary lixiviauong, and the fubfl^no^s ougfaft
to be previoufly ftirr^d up in th^. ^at^r beforo
the clear liquor is drawn oflf, oth$j5Wife the Wholo
mats might not be^- equttU; lixiviated, and ibme
parts might ^^n Efcape altogether from the ac^
tion of the w^sUer. W^ niuft likewift employ
frelh portiom of water in confiderabl^ quantity,
until it comes off entilrdy free from fait, which
we may afoertain by means of the hydrometci
formerly defcribed.

In experiments with fmall quftntities, this ope^
ration is conveniently performed in jugs or ma«
ttaffesi of glals, and by filtrating the liquor
through pap^r in a gla^s funnel* Wlien the fub»
ftance i% in larger quantity, it m^y be lixiviated
in a kettle of boiling- wateri and filtrated through
paper fupported by cloth in a wooden frames
PI. IL Fig. 3* a^d 4* ; and in operations in the
^y^ge way, the tub already mentioned muft be

•ii

^fa SECT.

ELEMENTS
SECT. IIL

Tb'u opentiofi b ofed tai feprariiig two fbb-

f faaces from each other, of which ooe at leaft

^•maft be fiuid, and wbofe degrees of roIatilitT- art

K ooaGderably dlffcreat. Bv this meam we obtain

r.m fait, which has been difloKed in water, in it9

eoncme form ; the water, by beating, become

combined with caloric, which renders it volatile,

while the particlcaof the fait being brought oear-

CT to each other, and within the fphere of that

mutual actradion, unite into the folid llate.

As it was long thought that the air had great
indoence upon the quantity of fluid evaporated,
it will be proper to point out the errors which
this opinion has produced. There certainly is
a conftant flow evaporation from fluids expofed
to the free air; and, though this fpecies of eva-
poration may be confidered in fome degree as a
folution in air, yet caloric has conSderabte in-
fluence in producing it, as is evident from the
refrigeration which always accompanies this pro-
ccls; hence we may confider this gradual ert-
poration as a compound folution made partly hi

1

OF CHEMISTRY. 453

air, and p^rdy in caloric. But the evaporation
which takes place from a fluid kept continually
boiling, is quite different in its nature, and in it
the evaporation produced by the a£tion of the
air is exceedingly inconfiderable in comparifon
with that which is occaiiooed by caloric. This
latter fpecies may be termed vaporization rather^
than evaporation. \ This procefs is not accelera-
ted in proportion to iht extent of evaporating ^
furfmce, but in proportion to the quantities of
caloric which combine with the fluid. Too fre<^
a current of cold air is often hurtful to this pro-*
eels, as it tends to carry off caloric from the wa->
ter, aivd confequently retards its converfion into
vapour. Hence there is no inconvenience pro-
duced by covering, in a certain degree, the vef-
fels in which liquids are evaporated by continual
boiling, provided the covering body be oi fuch
a nature as does not ftrongly draw off the calo-
ric, or, to ufd an expreflion of Dr Franklin's,
provided it be a bad conductor pf heat, in thiw
cafe, the vappurs efcape through fuch opening
as is left, and at leafl: sis much is evaporated,
frequently more than when free accefs is allowed
to the externa] air.

As during evaporation the fluid carried off by
caloric is entirely loft, being facrificed for the
fake of the fixed fubftances with which it was
combined, this procefs is only employed where
the fluid is of fmall value, as water, for inftance.

Ff3 But,

ELEMENTS

quvnoq^H

-But, when %lx fluid is of more coniieqw
tUTc [ecourietodiftill.'ition, in which procefl
pcT-lerre boiii the fixed fubllance :uid the volatile
fiiud. The vefleh employed fur evaporation an
bdfoos or pans of copper, filver, or lead, PI. IL
Ffg. 13. and 15. or capfules of glafs, purcelaiu,
or llone-ware, PI. II. A, Fig. 1. and j. PI. IJI.
Eig. 3. and 4. The bed utenfils for this pur-
pofeare made of the bottoms of glafs retorts and
itutrajfes, as their equal tbinnefs renders tben)
nwre fit than any other kind of glafs-veflel for
hearing, a brilk fire, and fudden alterations <4
^ heat aud cold, without breaking.

, As the method of cutting thefe glafs veiTels is
00 where defcribed in books, I fhall here give •
defcripttpn of it, that they may be made by che-
Bftifts for themfelves out of fpoiled retorts, ma-
trftlfes, and recipients, at a much cheaper rate
than any which can be procured from glab maiut*
feckurer*. The inftrupnent, PI. HI. i-ig. 5. con^
fiAJng of au iron ring AC.fi»ed Co the rod AB*
beving a, wooden handle i>, is employed as fol-
Igws; Make tlie ring red hot in ifac fire, and put
it upon the matrafs G, Fig. 6. which is to be
cut; when the glafs is fufficiently heated, throw
on a little, cold water, and it willgenerallv break
I Oxu^lyt at the circular line heated by the ring.

Small fliilk- or phiali of tfainglafe are cxiecd-

'ipggood vclTeis.iar evaporal ' ii quantities

Qffitud^ th che I The fire

tkably.

^

remarkably. One or more of thefe tnay be pla-
ced upon a fecond grate above the furnace,
PI. III. Fig. 2. where they will only experience
a gentle heat. By this means a great number of
experiments may be carried on at one time. A
glafs retort, placed in a fand-bath, and covered
with a dome of baked earth, PI. III. Fig. i. an-
iwert pretty well for evaporations ; but in this
way it is always confiderably flower, and is even
liable to accidents ; as the fand heats unequally^
and the glafs cannot dilate in the fame unequal
manner, the retort is very liable to breaks Some«
times the fand ferves exaAly the office of thd
iron ring formerly mentioned ; for, if a finglct
drop of vapour, condenfed into liquid, happens
to fall upon the heated part of the vefiTei, it
breaks circularly at that place. When a very
intenfe fire is necefiary^ earthen crucibles may
be ufed ; but we generally ufe the word evapo^
ration to exprefs what is produced by the tem-
perature of boiling watei, or not much highen \

Ff4 ' SECT.

456

£L£M£NT&

SECT. IV.

Of CrjftaBxatiw.

In this proGcTa the integrant parts of a <bli<
body, feparated from each other by ttie inta^,
ventioR of a fluidt are made to exert the mutoil
attradion of abnegation, foas to coakfce ant
reproduce a felid mala. When tbe particles of
8 body are oidy feparated by caloric, and tbe
fubftance is thereby retained in tbe liquid ftu^
all that is neceflary for making it cryftallize, ii
to remove a part of the caloric which is lodged

OF CHEMISTRY. 457

of their mutual atthUStion, the fait renciQins in
the fluid ftate ; but whenever either caloric or
water is not prefent in fuificient quantity, and
the attradipn of the particles for eaoh other be-
comes fuperior to the power which keeps them,
afunder, the fait recovers its concrete form, and
the cryftals produced are ^the more regular in
proportion as the evaporation has been flower
and more tranquilly performed.

All the phenomena we formerly mentioned
as taking place during the folution of falts, oc^
cur in a contrary fenfe during their cryftallixa*
tion. Caloric is difengaged at the inftant of
their afiuming the folid ftate^ which furniflies
an additional proof of fait being held in folu*
tion by the compound adion of water and car
loric. Hence to caufe falts to cryftallize which
readily liquify by means of caloric, it is not fuf«
ficient to carry off the water which held them
in folution, but the caloric united to them mult
likewife be removed. Nitrat of potafli, oxyge-
nated muriat of potaih, alum, fulphat of foda,
&c. are examples of this circumftance, as, to
make thefe falts cryftallize, refrigeration muft be
added to evaporation. Such falts, on the con-
trary, as require little caloric for being kept in
folution, and which, from that circumftance,
are almoft equally foluble in cold and warm
water, are cryftallixable by Amply carrying off"
the water, which holds them in folution, and

even

458

ELEMENTS

even recoTcr their folid ftate in boiling water ;
fuch are futphac of lime, muriat of potafh and of
foda, and feveral others.

Tbe art of refining faltpc&e depends upoa
thefe properties of falts, and upon tbeir different
degrees of folubility in hot and coU water. This
fait, as produced in the manu&dories bj the
firft operation, is cos^ofed of many different
falts ; fome are deliqudcent, and not fufceptible
of being cryftallized, fiicb as the nitrat and mu-
riat of lime ; otfaers sra almoft equally foUibla
in hot and cold water, a> the moriats of potaflt
and of fbda ; and laftly, the fiiltpetre, or nitrar
of potaih, is greatly more foluble in hot than it
is in cold water. The operation is begnn by
pouring upon this mixture of iaits, as much wa-
ter as wilt hold even the Icaft foluble, the mu-

OF CHEMISTRY.

459

ture of faltpetrt, aqd other falls \ by farther eva-
poration, crude faltpetre, or rough-petre, as the
workmen call it, is procured from it, and this
is purified by two frefh iolatioas and cryfiallixa^
tioos.

The deliquefcent earthy lalta which do not
contain the pitricwad arc iTJei^ed in this na-
Bu&dure ; but thO(c wtedi confift of that aod
neutraliaed by an cOrthy hafe are diiTolTed in
water, the earth ia precipitattd by qjeaos of pot-'
afii, and allowed to.fubfide i tbe clear' liquor ia
thea decanted, evaporated, aud allowed to aryf-*
tallize. The above management for refining
iiiltpetre; may titrve n a general .rule for Icpa-'
rating^ f^ts &om each oth«r whkh happen to
be coixed together. Ttw RaCurc of each muft
he coofidercd, the tKOi^rtion in which each dif-
folves in ^v«d quantities of water, and tbe dif-
icrent fdubility of eadi in hoc and cold waters
If to thefe we add the: pn^rty whidiXame &ltft
poflefs, of being foluble in allijohol, or in a mix*
ture of alkohol and water, we hare many re-
fourcet for l^iftrating falts Sr^n each other by
means of cryftallization, though it muft be al-
lowed, that it is extremely difficult to render this
reparation perfeAly complete^

The veSeU uCed for cryfl^lUzation are pan»
of earthen ware, A, PI. II. Fig. i. and 2. and
]argeflat diQies, 1*1.111, Fig. 7. 'VVhcn h fal'ine
folutton is to be espofed to a flow evaporation

460

ELEMENTS

t

in the heat of the atmofphere, with free accelil
air, veffels of forac depth, Plate III. Fig 3.
be employed, that there may be a confideraS
body of liquid ; by this means the cryilaU ptt
duced are of confiderable fiie, and remarkaW
regular in their figure.

Every fpecies of fait cryftalliies in a peculil
form, and even each fait varies in the form 4
its cryftals, according to circumftance5, whiel
take place during cryftalUzation. We muft i
from thence conclude, that the faline particles a
each fpecies are indeterminate in their figurei
The primitive particles of all bodies, efpecialH
of falts, are perfectly conftant in their fpeciB
forms ; but the cryftals which form in our e
periments are compofed of congeries of minul
particles, which though perfeftly equal in I
and (hape, may affume very diflimilar arrangi
ments, and confequently produce a vaft varid
of regular forms, which have not the fmal
apparent refemblance to each other, nor to CH
original cryftal. This fubjeft has been very aU
treated by the Abb6 Haiiy, in feveral memoi
prefented to the Academy, and in his work
on the ftru£lure of cryftals : It is only neccllal
to extend generally to the clafs of falts the pil
ciplcs he has particularly applied to fome <
ftallized flones.

OF CHEMISTRY.

4«i

SECT. V.
Of Simple Di/Hliatioa,

As diltlllation has two diltinA objefts to ac-
compliih, it is divifible into firaple and com-
pound ; and, io this foSion, I mean to confine
myfelf entirely to the former. When two bo-
dies, of which one is more volatile than the
other, or has more affinity to caloric, are fub-
mitted to difiillatioo, our intention is to fepa-
rate them from each other : The more volatile
fubftance aSumes the form of gas, and is after-
wards condenfed by refrigeration in proper vef-
fels. In this cafe diftillation, like evaporation,
becomes a fpecies of mechanical operation, which
feparates two fubftances from each other without
decompofing or altering the natare of either. In
evaporation, our only objed is to preferve [the
fixed body, without paying any regard to the
voladle matter; whereas, in dillillation, our prin-
cipal attention is generally paid to the volatile
fubftance, unlefs when we intend to preferve
both the one and the other. Hence, fimple di-
ftillation is itothing more than evaporation pro-
duced in clofe vefiels.

The moft fimple dtftilliag '

4^

ELEMENTS

of bottle or matrafs. A, PI. III. Fig. 8. wbicb hu
been bent from its original form BC to BD, and
which is then called a retort ; when ufed, it is
placed either in a reverberatory furnace, PI. XIII.
Fig. 2. or in a fand-bath under a dome of baked
earth, PI. III. Fig. r. To receive and condenfe
the produfls we adapt a recipient, E, PL III.
Fig, 9. which is luted to the retort.

Sometimes, more efpecially in pharmaceutical
II operations, the glafs or done ware cucurbit. A,

^P with its capital B, Fl. III. Fig. iz. or the glais

^K alembic and capital. Fig. 13. of one piece, is

K employed. This Utter is managed by means of

H a tubulated opening T, fitted with a ground

H Hopper of cryftal ; the capital, both of the cu-

H curbit and alembic, has a furrow or trench, p- q

H intended for conveying the condenfed liqaot

^1 into the beak RS, by which it runs out. A^

^P in almoft all didillations, expantive vapours are

^K produced, which might burft the veffels emploj-

^H ed. we are under the neccdity of having a iinall

^m hole, T, Fig. 9. in the balloon or recipieat,

^B through which thefe may find vent ; heocc, m

^1 this way of diftilling, all the produfts which arc

^1 permanently aeriform are entirely loft, and even

^P fuch as diUicukly lofe that Hate have not fufficient

^H fpace to condenfe in the balloon : This appara-

^H tus is not, therefore, proper for experiments of

^H invelligation, and can only be admitted in the

^1 ordinary operations of the laboratory or in

OF CHEMISTRY. 46}

pharmacy. In the article. appropriated fbr cooki
pound diilillatibn^ I flialL explain the vaiioui
methods which liave been contrived foe prefer-*
ving the whole produAs from bodies in this pro^
cefs.

As glafs or earthen veflels are very brittle
and do not readily bear fudden alterations: of
heat and cold, . every ^rell regulated laborat6ry
ought to have one or more alembics of metal
for diftilling water, fpiritoUs liquorSi eflential
oils, &c. This apparatus confifts of a cucurbit
and capital of tinned popper or brafs, Ph III.
Fig. 15. and 16. which, when judged proper,
may be placed in the water-bath, D, Fig 17.
In diftiUation, efpeciallyof fpiritous liquors, the
capital muft be furniftied with a refrigeratory,
SS, Fig. 16. kept continually filled with cold
water ; when the water becomes heated, it is
let off by the ftop-cock, R, and renewed with a
frefh fupply of cold water. As the fluid diftil*^
led is Converted into gas by means of caloric
furnilbed by the fire of the furnace^ it is evi«
dent that it could not ' condenfe, and, Confe*
quently, that no diftillation, properly fpeaking,
could take place, unlefs it is made to depofit in
the capital all the caloric it received in the cu-*
curbit ; with this view, the fides of the capital
muft always be preferved at a lower tempera-
ture than is neceflary for keeping the difttUing
* ^Hanoe in the ftate of 1^ and the \^ater in

the

464

£I.£H£NTS

tbe Tcfrigentoiy is mttniirii fiir this pmrpufc
Water b cooTcrted into gu by the temperaton
of 212*. alkobol by 181.75', *^ dther bj 104";
hence tbete fubftances cumat be diftilled, or i»>
ther thej will flj off in Cbe ftate of gas, tuileft
the tempenture of the rdngenioiy be kept un-
der theie refpcdive degrees.

In tbe diftiUatioa of fpiritous, and other ex-
panEre liquors, cbe above defcribed refrigerato-
rr is not ru£cicnt lor eondenfing all the Tapoms
which 2ii£e ; in this cafe, therefore, infiead of
teceiTing the diftilkd liquor immediatclj from
the beak TU, of the a^tal into a recipient,
a worm is interpofad between them. This in-r
ftruaem is repiefentcd PL IIL Fig. z8. contain-
ed in a worm-tub of tinned copper ; its confifts

OF CHEMISTRY. 465

two pfoduds of different degrees of volatility^ ;
or to remove the receiver to a greater diftance
from the furnace, that it may be lefs heated.
JBut thefe, and feveral other more complicated
inftruments of ancient contrivance, are far from
producing the accuracy requifite in modern che-
roiftry, as will be readily perceived when I come
to treat of compound diftillation.

SECT. VI.

Of Sublimation.

This term is applied to the diftillation of fub-
jftances which condenfe in a concrete or folid
form, fuch as the fublimation of fulphur, and of
muriat of ammoniac, or fal ammoniac. Thefe
operations may be conveniently performed in
the ordinary diftilling veflels already defcribed,
though, in the fublimation of fUlphur, a fpe-
cies of veflels, named Alludels, have been ufu-
ally employed. Thefe are veflels of ftone or
porcelain ware, which adjuft to each other over
a cucurbit containing the fulphur to be fubli*
; med. One of the bed fubliming veflels, for fub-
* ^^-iiocf "»bich are not very volatile, is a flafk,

1^ funk about two-thirds into a
G g fand"?

466

CLEMENTS

fand-bath ; but in this way we are apt to lofe i,
part of the produfts. When thefe are wilhed
to be entirely preferved, we muft have recourfe ,
to thepneumato-chemical diflilling appai
be defcrjbed iq (he following chapter.

CHi

d^ CH^MlSTItT. VJ4$7

\

V

• • • m *

»■.

••ft," _ ■»t»i*r| f

CHAP, .VI.

Of Pneumam-chmical DijNUations, Metallic Dif-
folutionSf nnd fome ' other Operations which re-
quire very complicated Inftnmenfs.

SECT. I.

# .

Of Compound and Pneumato^chemical I)i/lillationi.

IN the preceding chapter, I have otily treated
of diftUlatioh as a iimple operation, by which
two fubftances, difiering in their degrees of vola-
tility, may be feparated from each other; but dif-
tillation often adually decompofes the fubftaq-
ces fubmltted to its aAion, and becomes one of
the moft complicated operations in chemiftry.
In every diftillation, the fubftance diililled muft
be brought to the (late of gas, in the cucurbit or
retort, by combination with caloric : In fimple
diftillation, this caloric is given out in the re-
trij^eratory or in the worm, and the fubftance
^" ili rticovcrs its liquid or folid form; but the
'Ces fubmitted to compound diftillation

G g 2 ' are

468

ELEMENTS

are abfolutely decompounded ; one part;'
inftance the carbon they contain, remains 6xed
in the retort, and all the reft of the eleaeots
are reduced to "gafles of different kinds. Some
of thcle gaffes are fufcqitibVe of being condeii.
fed, anJ of recovering their folid or liquid forms,
while others ate permanently aeriform ; one part
of thefe arc abforbablc by water, fome by the al-
kalies, and others are not fufceptible of being
abforbed at all. An ordinary diiUIIing appara-
tus. fuch as has been defcribed in the precediiw
chapter, is quite infufficienC for retaining or for
feparating thefe diverli6ed produifls, and we are
obliged to have recourfe, for this purpole, to
methods of a more complicated nature.

The apparatus 1 am about to defcribe is cal-
culated for the moft complicated diflillations, anJ
may be fimplified or exiended according to cir-
cuinftances. It confiftsof a tubulated glafs retort
A, PI. IV. Fig. 1, having its beak fitted to a tu<
bulated balloon or recipient BC ; to the upper
orifice D of the balloon a bent tube DE/5f is ad-
jufted, which, at its other extremity f, is plun-
ged into the liquor contained in the bottle L,
with three necks xxx. Three other fimiUr
bottles are conneded with this firft one, by
means of three fimilar bent tubes difpofed in
the fame manner ; and the fartheft; neck of the
laft bottle is conneded with a jar in a pt^cu>
mato-chemical apparatus, by means of a bent
tube.

OF CHEMISTRY. 4^9

tube *. A determinate weight of diftilled water
is ufually put into the &r& bottle, and the other
three haye each a folufionof cauftic potafli in
water. The weight of all thefe bottles^ and of
the water and alkaline folution the;)&contain,muft
be accurately afcertained. Everything being thus
difpofedy the jundures between the retort and re«
cipient, and of the tube D of the lattet^ muft be
luted with fat lute, covfcrcd over with .flips qf
linen, fpread with lime and white of eg^ ; all
the other jundures are to be fecured by a lute
jnade of wax and rofin melted together.

When all thefe difpofitions are completed,
and wfien^ by means of heat applied to the re-
tort A, the fabftance it contains becomes der
compofed, it is evident that the leaft volatile
produces mud condenfe: or fubli me in the beal^
or neck of the retort itfelf, where moft of the
concrete fubftances will fix themfelves. l*h^
Ujnore volatile fubftances, as the lighter oils^ am<»
^Mniac, and feveral others^ will condenfe. in the
Iripient GC, whilft the gaffes, which are not
Wglftble of condenfation by cold, will pafs on
/ttie tubes, and boil up through the liquors
*V feVerai bottles. Such as are abforbablo
1 G g 3 ^ by

# ■

jvprdentsdon of this apparatus, ?1. IV. Fig. i^
;^ mncli i^ctt^r i^ea of its difpofirion than caa
Bvea by the moft laboured defcriptioDw^-T. '

47*

ELEMENTS

ty water will remain in the firft bottle, and
tbofe which cauAic alkali can ablorb will re.
main in the others ; while fuch gafles as are
not Aifceptible of abforption, either by water or
alkalies, will efcape by the tube RM, at the end
of which they may be received into jars in 'a
pneumato-chemicai apparatus. The carbon and
fixed earth, &c. wliich form the fubftance or »■
(iduum, anciently called caput mortuum^ renuui
behind in the retort.

In this manner of operating, we have alwap
a very material proof of the accuracy of tbt
analyfis, as the whole weights of the prododi
taken together, after the procefs is iinifbed,
muft be cxatftiy equal to the weight of the on*
ginal fubftance fubmitted to diftillation. Ueocc,
for inilance, if we have operated upon eight
ounces of ftarch or gum arable, the weight of
the charry rcBduum in the retort, together witb
ihat of all the produfls gathered in its neck and
the balloon, and of all the gas received into the
jars by I he tube RM added to the additiooal
weight acquired by the bottles, muil, when ta-
ken together, be exacUy eight ounces. If the
produC) be lels or more, it proceeds fron tf>
' : experimeij^Mft be repeated until
M'liich ought
ht grains in the

pota

; Tobnai

or CHEMISTRt. 47^

tn experiments of this kind, I foi* a long time
met with an ahnoft infunnountable difficulty^
which muit at laft have obliged me to defift alto*
gether, but for a very fimple method of avoid-
ing itt pointed out to me by Mr Haflenfratx^
The fmalleft diminution in the heat of the fur-^^
tiaccy and many other circumftances infeparable
from this kind of experiments, cau& frequent
reabforptlons of gas ; when this dccuns, the water
in the ciftern of the pneumato-chemical appara-
tus ruihes into the laft bottle through the tube
RM ; the fame circumftance happens from one
bottle into another, and the fluid is often forced
even into the recipient C. This accident is pre-
vented by ufing bottles having three necks, as
reprefented in the plate, into one of which, in
each bottle, a capillary glafs-tube St, st^ st, si, is
adapted, fo as to have its lower extremity / im*
merfed in the liqUor. If any abforption takes
place, either in the retort, or in any of the bot-
tles, a fufficient quantity of external air enters,
by means of thefe tubes, to fill up the void ; and
we get rid of the inconvenience at the price of
having a fmaU portion of common air mixed with
the produAs of the experiment, which is there-
by prevented from failing altogether. Though
thcfis tubes admit the external air, they cannot
jj^jj^mBritt any of the gafleous.fubftances to efcape,
ify are always (hut below by the water of
ttles.

Gg4 It

ELEMENTS!

b ■ niifctt Ak, ia Ae coorfc of expm-
qoor of the bot-
s in proportion to the
I W tke gB or ait co&taiocd in
e iydrt emiiDed by
f of tbc column of fluid
t bonlcs. I/«e
■ tfaree inches
s of VB*

m ■■ Ac ciAos MR OE c^^ieaea apyaiMiif A-
e ttf the n*c BLM, sail afioving
K to he oalf cqsal to thai
has ihe H in the 6rA
[ to twelve
■rfl tfaerctbre rife
cSkcaHHcted with the
;ID the

■ dieBiMiii ltB£
tn^ne a fiwihr tahc hetscea the mart aad
nofitmi Md B the tabeisDoc JMaiiiftil in
laid tt its lover extroniiT, aBCil fane hiM coL
iBdcd ia die pnpcta of the dtftibnoc; itt i^
pa end Baft be &IIC M itftvkh a fittlchae, lb
a* lo be opcoed accofdii^ to nceeCty, «■ ^

OF CHEMISTRT. 4^5

there is fufficient liquid in the recipient to fe-
cure its lower extremity.

This apparatus cannot be ufed in very accu-
rate experiments, when the fubftances intended
to be operated upon have a very rapid adion
upon each other, or when one of them can on-
ly be introduced in fmall fucceflive portions, as
in fuch as produce violent eflfervefcence when
mixed together. In fuch cafes, we employ ^
tubulated retort A, PI. VII. Fig. i. into which
one of the fubftances is introduced, preferring
always the folid body, if any fuch is to be treat-
ed, we then lute to the opening of the retort a
bent tube BCDA, terminating at its upper ex-
tremity B in a funnel, and at its other end A in
a capillary opening. The fluid material of the
experiment is poured into the retort by means
of this funnel, which muft be made of fuch a
length, from B to C, that the column of liquid
introduced may counterbalance the refiftance
produced by the liquors contained iu all the
bottles, PL IV. Fig. i.

Thofe who have not been accuftomed to ufe
the above defcribed diftilling apparatus, may
perhaps be ftartled at the great number of open-
ings which require luting, and the time necef-
fary for making all the previous preparations in
experiments of this kind. It is very true tliar,
Hw* * into account all the neceflary weigh-
terials and produds, both before and

after

474

ELEMENTS

after the experimenti, thefe preporatoty andfiiC*
ceeding fteps require much more time aitd atten*
lion than the expcrtment itlel£ But. when the
experiment fucceeds propolj, we are well re-
warded fur all thetimeuid trouble beftowed, a^
by one procefs carried on in thii accurate mad-
ner, much more juft and cxtenfive knowledge is
acquired, of the nature of the vegetable or ani-
mal fubftance thu« fiibmitted to inTeftigation,
than by many weeks afidoous labour in the or*
dinary method of proceeding.

When in want of bottles with three orificea*
thofe with two may be ufed ; it i% even poffible
to introduce all the three tubes at one opening',
fo as to employ ordinary wide-mouthed bottle^
provided the opening be fufficiently large. In
this cafe we mud carefully fit the bottles with

OF CHEMISTRY.

473

SECT. II.

QJ MttaOk Difolutiotu,

I have already polntied out the difference he*
tween iblutkm of ftlta in watw a&d metallic di£^
ibiutioos. The .former requires no paiticuliic
veflels, whereas the latter requires very compli*
cated veffela of late iuveotioo, that we may not
loiJe any of the produ^s of the experiment, and
may thereby procure truly conclufive reAilts ot'
the phenomena which, occur. The jnetals^ in
general, diflbhe ia acids with efierveJcence.
which is only a motion. excited in the folvent by
At di£engagement of a great munber of bubbles
of air or aeriform fluid, which proceed from the
furface of the metal, and break' at die furface of
the liquid.

Mr Cavendlih and Dt Prieilly were the firft
inventors of a proper apparatus for collei^ing
thefe elafiic fluids. That .of Dr Frteftly i$
extremely fimple, and conflfts of a bottle At
PL VIL Fig, 2. with its cork B, through which
pa&ithc bent glafs tube £C. which is engaged
under a. jar fiHtd with w^ter in the pneumato-
obemical apiJaralu^, or limply in a baibu full of
The meml is Hrft introduced into the
bottle.

--^

ELEMENTS.

tie, th« acid is iben poured over it, and tfitf
lottle is innanlly clofec! with its cork and tube,
M repreletiied in the plate. But this apparatus
has it* inconrenicncies. When the acid is much
concentrated, or the metal much divided, the c;f-
frrrefcencc begin? before we have lime to cork
the bottle properly, and H^me gas efcapes, byjj
which we are prevented from afcertaining the
quantity difcngaged with rigorous exaflnefs. IiS
the nest place, when we are obliged to employ
heat, or when heat is produced by the procefe, 1
a part of the acid diflils, and mixes with the wa- 4
ter of the pneumalo-chcmical apparatus, by which. |
means we arc deceived in our calculation of tho
qaantity of acid decompofed. Befides tbefcj
the water in the cjftem of the apparatus abforb
all the gas produced which is fufccptible of ab-
forption, and renders it impoffiblc to colled thefe
without lofs.

To rcfiiedy thefe inconreniencies, I at 6rft^
ufed a bottle with two necks, PI. VIl. Fig. 3. in^ 1
to one of which the glafs funnel B C is luted Cam
as to prevent any air efcaping ; a glafs rod D El
is fitted with emtry to the funnel, fo as to fenref
the purpofe of a ftopper. When it is ufcd, tbft
roarter to be diffolved is firft introduced into t
bottle, and the acid is then permitted to pafs ia
as flnwty as we pleafe. by raiting ttHub& i
irently as ofico as is neceflkry umr'
produced.

OF CHEjMISTRT. .477

Another metbod has been fince employed^

which, fenres. the fame purpofe, and is pcefer-

able to the laft defcribed in fome inftances. This

confifts in adapting to one of the mouths of the

bottle A, PL Vll. Fig- 4. a bent tube D E F G,

having a capillary opening at D, and ending in

a funnel at G. This tube is 'fecurely luted to

the mouth C of the bottle. When any liquid

is poured into the funnel^ it f^^Us down to F ;

and, if a fuilScient quantity be added, it pafles

by the curvature E, and falls flowly into, the

bottle, fo long as frcfh liquor is fupplied at the

funnel. The liquor can never be forced out of

the tube, and no gas can efcape. through it, be-

. . . '
caufe the weight of the liquid ferves the purpofe

of an accurate cork.

To prevent any diftillation of acid, efpecially
in diflblutions accompanied with heat, this tul^e
is adapted to the retort A, PL VII. Fig. i. and
a fmall tubulated recipient, M, is applied, in
which any liquor which may diftil i? condenfed.
On purpofe to feparate any gas that is abforb-
able by water, we add the double necked bot-
tle L, half filled with a folution of xauftic pot-
a(h : the alkali abforbs any carbonic acid gas,
and ufually only one or two other gaffes pafs
ijito the jar of the connected pneumato-chemi-
, fcal apparatus through the tube N O. In the
firft ct^gter.of this third part we have directed
\niy f\ ^xt to be feparated and examined.

If

'478 ELEMENTS

•iTintelxtttle of iBudioe foliitkm be aot tlioagfat
IhflScient, two, three, or more, maybe adde^

SECT. IIL

d

Apparatus neeeffary in Expfrimentt apoa Vtmrnt
and Patrcfa&ive FermentatUns.

^SPi' thefc operations a peculiar apparatus^

*efpecially intended for thi* kind of experlmcDt,

is reqiiifite. The one I am about to defcribc is

jinall^- adopted, as the beft calculated for the

; purpofe, after numerous corrections andiimprove-

ments. It coniids of a large matrafs, A, PL %.

Fig. I. holding about twelve pints, with a cap of

brafsaJ, ftrongly cemented to its mouth, and

^nto which is fcrewed a bent tube c d, futniflieJ

with a ftop-cock e. To this tube is joined the

L'slafs recipient B, having three openings, one of

L vhich communicates with the bottle C, placed

L below it. To the pollerior opening of this re-

^ cipient is fitted a glafs tube g h i, cemented at g

I and i to collets of brafs, and intended to contain

a very dcJiquefcent concrete neutral fait, fuch

as nitrator muriat of lime, acetite of potafh, &c.

This tube communicates with two bottles D

■ and E, filled to x and^ withafulutionof cauflic

potalli.

Ot OHEMISTItT. 479

All the p^rts of this machine are joined toge*
thet by accorate (brews, and the touching parts
have greafed leather Intcrpofed, -to prevent any
paflage of air. £ach piece is likewife farhiflied
with two ftop-cocks, by which its two extremi-
ties n^ay be clofed/ fo that we can weigh each fe-
parately at any period of the operation.

The fermentable matter, fuch as fugar, with
a proper quantity of yeaft, and diluted with wai-
ter, is put into the matrafs. Sometimes, when
the fermentation is too rapid, a confiderable
quantity of froth is produced, which not only
fills the neck of the matrafs, but pafles into the
recipient, and from thence runs down into the
bottle C. On purpofe to coUedl this fcum and
muft, and to prevent it from reaching the tube
filled with deliquefcent falts, the recipient and
conneded bottle are made of confiderable capdl-
city.

In the vinous fermentation, only carbonic
acid gas is difengaged, carrying with it a fmall
proportion of water in folution. A great jmrt
of this water is depofited in paffing through the
tube ^ b I, which is filled with a deliquefcent
fait in grofs powder, and the quantity is afcer-
tained by the augmentation of the weight of the
fait. The carbonic acid gas bubbles up through
the alkaline folution in the bottle D, to which
eyed by the tube klm. Any fmalj
dch may not be abforbed by this

firft

48o ELEMENTS

firft bottle is fecured by the folution in the fc
cond bottle E, Co that nothing, in general, pafles
into the jdr F, except the common air contained
in the vefiels at the commencement of the expe-
riment.

The fame apparatus anfwers extremely well
for experiments upon the putrefaftive fermen-
tation; but, in this cafe a confiderable quantitj
of hydrogen gas is difengaged through the tube
q r s t u, by which it is conveyed into the jar F;
and, as this difengagement is very rapid, eipe.
cially in fummer, the jar mud be frequently
changed. Thefe puttefadive fermentations re-
quire conftant attendance from the above circuno-
ilance, whereas the vinous fermentation hardly
needs any. By means of this apparatus wc can
afcertain, with great precifion, the weights of the
fubftances fubraitted to fermentation, and of the
liquid and aeriform produfts which are difenga-
ged. iWhat has been already faid in Parti.
Chap. XIII. upon the produ<fts of the vinoiK
fermentation, may be confulted.

OF CHEMISTRY. 4

SECT. IV.

Apparatui for tbe Decompojition of Water.

\

Having already given an account, in the firft
part of this work, of the experiments relatiye
to the decompofition of water, 1 ftiall avoid any
nnneceflary repetitions, and only give a few
fiimmary obfervations upon the fubjeiS in this
{e^ion. Tbe principal fubftances which have
the power of decompofing water, are iron and
charcoal; for 'which purpofe, they require to
be made red hot, othcrwife the water is only re-
duced into vapour, and condenfes afterwards by
refrigeration, without fuftajning the fmalleft al-
teration. In a red heat, on the contrary, iron
or charcoal carry off the oxygen from its union
■with hydrogen ; in the firft cafe, black oxyd of
■iron is produced, and the hydrogen is difengaged
■■pure in form of gas ; Jn the other cafe, carbonic
acid gas is formed, which difengages, mixed with
the hydrogen gas, and this latter is commonly
carbonated, or holds carbon in folution.

A mulket-barrel, without its breach pin, an-
fwers exceedingly well for the decompofition of
*ater, by means of iron, and one fliould be
H h chofea

48>

ELEMENTS

chofen of confiderable length, and pretty ftrong.
When too lliort, fo as to run the rilk of heating
the lute too much, a tube of copper ntufl be
itrongly foldered to one end. The barrel is pls«
ced in a long furnace, CDEF, PI. VII. Fig. ii.
fo as to have a few degrees of inclination from E
to F i a glafs retort A, is luted to the upper ei-
tremity E, which contains water, and is placed
upon the furnace VVXX. The lower extiemi*
ty F is luted to a worm SS, which is conncded
with the tubulated bottle H, in which any water
dilUiled without decompolition, during the ope-
ration, coUeds, and the difengagedgas is carried
by the tube K.K to jars in a pneumato-cUemical
apparatus. Indead of thereton, a funnel taay be
employed, having its loner part ihut by a fit^
cock, through which the water is allowed to
drop gradually into the gun-barrel. Immediateljr
upon getting into contad with the heated part of
the iron, the water is converted into ftearo, and
the experiment proceeds in the fame manner as
if it were furnilhed in vapours from the retort.
In the experiment made by Mr Meuibler and
me 'fcfore a committee of the Academy, we ufed
every precaution to obtain the greateft pofiible
prccifion in the refult of our experiment, having
even exhaulled all the veffels employed before wc
began, fo that the hydrogen gas obtained might
be free irom any mixture of aiotic gas. The re-

OF CHEMISTRY. 483

fults of that experiment will hereafter be given
at large in a particular memoir.

In numerous experiments, we are obliged to
ufe tubes of glafs, porcelain, or copper, inftead
of gun-barrels ; but glals has the difad vantage of
being eafily melted and flattened, if the heat
be in the fmalleft degree raifed too high ; and
porcelain is moftly full of fraall minute pores,'
through which the gas efcapes, efpecially when
comprefled by a column of water. For thefe
reafons I procured a tube of brafs, which Mr de
la Briche got caft and bored out of the folid for
pie at Strafburg, under his own infpeftion. This
tube is extremely convenient for decompofing
alkohol, which refolves into carbon, carbonic
acid gas, and hydrogen gas ; it may likewife be
ufed with the fame advantage for decompofing
water by means of charcoal, and in a great numf
hn of experiments of this nature.

H h a CHAP.

4U

£L£M£NTS

CHAP. VII.
0/ It: Csmpofitioa and jffpHaUioM of Zvfr/*

THE necellitr of properiv fccuruig the jancr
tunrs of chemical. Tcilcls, to prerent tbc
eiVdi>f oi' anj of the pioduds of expcrioaeiit^
inuit be lulfictently apparent ; for thb purpoA
lutes urc cmploved, which ought to be of fuch ■
!M:ure s$ to be equally impenetraUe to the mot
iUb;'.l« Ltihttonccs as ^al's itiel^ thioogfa whidi
viily t.-^ocic can ctcape.

OF CHEMlSTkr. .4S5

For fuch cafes, the following fat lute is the
beft hitherto difcovered, though not without its
difadvantages, which fliall be pointed out. Take
very pure and dry unbaked clay, reduced to a
fine powder, put this into a brafs mortar, and
beat it for feveral hours with a heavy iron peftlp,
dropping in (lowly fome boiled lintfeed oil ; this
is oil which has been oxygenated, and has ac-
quired a drying quality, by being boiled with
litharge. This lute is more tenacious, and ap-
plies better, if amber varnifh be ufed inftead of
the above oil. To make this varnifti, melt fome
yellow amber in an iron laddie, by which opera-
tion it lofes a part of its fuccinic acid, and eflen-
tial oil, and mix it with lintfeed oil. Though
the lute prepared with this vamifh is better than
that made with boiled oil, yet, as its additional
expence is hardly compenfated by its fuperior
quality, it is feldom ufed.

The above fat lute is capable of fuftaining a
very violent degree of heat, is impenetrable by
acids and fpiritous liquors, and adheres exceed-
ingly well to metals, (lone- ware, or glafs, provi-
ding they have been previoufly rendered per-
feftly dry. But if, unfortunately, any of the
liquor in the courfe of an experiment gets
through, either between the glafs and the late,
or between the layers of the lute itfelf, fo as to
moiften the part, it is extremely difficult to clofe

H h 3 the

486

ELEMENTS

tlie opening. This is the chief inconvenience
which attends the ufe of fat lute, and perhaps
the only one it is fubjeft to. As it is apt to fof-
len by heat, we muft furround all the jonclares
with flips of wet bladder applied over the luting,
and fixed on by pack-thread lied round both
above and below the joint ; the bladder, andcon-
fequentiy the lute below, muft be farther fecu-
red by a number of turns of pack-thread all over
it. By thefe precautions, wc are free fFom evefy
clanger of accident ; and the junfturcs fecured
in .this manner may be confidered, in experi-
ments, as hermetically fealed.

It frequently happens that the figure of the
juni5tures prevents the application of ligatures,
which is the cafe with the three-necked bottles
formerly defcribed ; and it even requires great
addrefs to apply the twine without fhaking the
apparatus ; fo that, where a number of jumflures
require luting, we are apt to difplace feveral,
while lecuringone. In thefe cafes, wc may fub-
flitute flips of linen, fpread with white of egg
and lime mixed together, inftcad of the wet
bladder. Thefe are applied while ftill moift,
and very fpeedily dry and acquire conlidcrable
hardnefs. Strong glue diflblved in water may
anfwer inflead of white of egg. Thefe fiUec
arc ufefully applied likewifc over junctures luted
together with wax and rofin.

Before

OF CHEMlSTRt. 487

' BAfbfe^ptyihg d* Itftcf, aU tht junautcs if
the veffels mnft be atecurately and firmly fitted
to eachoth^r, fo a^ not to admit of being mo-
ved. If the beak of a rttort is to be luted to
the iieclk of a recipient!, they ought t6 fit pretty
accurately ; otherwife we muft fix them by in-
troducing fiiort pieces of foft wood, or of cbrt
If the dirproportion between the two be very
confiderable, we diufi: employ a cork which 6ti
the neck of the ftti^ieht, having a circular hdief
of proper dimenfions to admit the beafkof the
fetort. The fafrtc precaution is neceflary in
adapting bent tubes ta the hecks of bottles
in the apparatus reprefented PI. IV. Fig. i.
and others of a fimilat nature. Each month of
each bottle mutt be fitted with a cork, having 9
hole made ^ith a round file of a proper fixe for
contamtng th^ tube. Aiid, when one mouth b
intended to admit two or more tubes, whichf
firequemly happens when we have not a: fuffi^
cient number of bottles with two or three neck^,
we mnf! ufe a cork with two' or three holes,
PL IV. Fig. 8.

When the whole apparatus vs thus folidly
joined, fo that no part can play upon another,
we begin to lute. The lute is foftened by
kneading and rolling it between the fingers,
with the affiftance of heat, if neceflary. It is
rolled into little cylindrical pieces, and applied
to the junduresi taking great care to make it

H h 4 »PPIv

Z L £ M £ N T S

f cU^ mAsAcsc fiinlj, in ctci^ pan') •

I IK i^fffiBd orer Uie firft, fb as Co pa&

P k«BaK& §i^aaA fb on till each jundure be

coicned ; after this, the flips of Mid-

ioe^ as abore direded, muft be caie-

[ fifly ifpfied over aQ. Though this operatioa

r doaaeij fimple, j'ct it requires pe-

^ cAk ddicicj and managcmeot ; great care moS

ke tdza not to diftorb one juodure whilit liu

ting another, and more cfpecialljr when applying

I ilie fiUets and ligatures.

Before beginning any experiment, the clofe*
ttt& of the luting ought always to be previoofly
tried, either by fiightly heatmg the retort A,
PL IV. Fig. 1. or by blowing in a little air by
fomc of the perpendicular tubes S s s s ; the al-
teratioD of ptelTure caufes a change in the lerel
of the liquid in thefe tubes. If the apparatut
be accurately luted, this alteration of level will
be permanent \ whereas, if there be the fmallcft
opening in any of the jun^ures, the liquid trill
very foon recover its former level. It muft al-
ways be remembered, that the whole fuccefsof
experiments in modern chemiftry depends upon
the exadlnefs of this operation, which theiej
requires the utmoft patience, and mod att
accuracy.

It would be of infinite fervicc to enable c
mifts, efpecially thofe who are engaged in e
matic proccfles, to difpenfe with the ufe of li

OF CHEMISTRY. 489.

or at leaft to diminifh the number neceflary in
complicated inllruments. I once thought of
having my apparatus conftru£ted fo as to unite
in all its parts by fitting with emery, in the way
of bottles with cryftal (toppers ; but the execu-
tion of this plan was extremely difficult. I have
fince thought it preferable to fubftitute columns
of a few lines of mercury in place of lutes, and
have got an apparatus conftruded upon this
principle, which appears capable of very conve*
nient application in a great number of circum-
fiances.

It confiils of a double necked bottle A, PL XII.
Fig. 12. ; the interior neck b c communicates
with the infide of the bottle, and the exte-
rior neck or rim d e leaves an interval between
the two necks, forming a deep gutter intended
to contain the mercury. The cap or lid of
glafs B enters this gutter and is properly fitted
to it, having notches in its lower edge for the
paflage of the tubes which convey the gas,
Thefe tubes, inftead of entering diredlly into
the bottles as in the ordinary apparatus, have a
double bend for making them enter the gutter,
as reprefented in Fig. 13. and for making them
fit the notches of the cap B ; they rife again
from the gutter to enter the infide of the bottle
over the border of the inner mouth. When the
tubes are difpofed in their proper places, and
♦he cap Qrmly fitted on, the gutter is filled with

3 mercury,'

490

ELEMENTS

mercury, by which means the bottle is con»-
pletely excluded from any communication, ex-
cepting through the tubes. This apparatus tnaf
be very convenient in many operations in whicV
the fuhftances employed have no aftioR upaOf
mercury. PL XII. Fig. 14. reprefents an appa-'
ratus upon this principle properly fitted tOft-
thcr.

Mr Seguin, to whofe aftive and intelligent
affiftance I have been very frequently much in-
debted, has bcfpoken for me, at the glafs-houfes,
fomc retorts hermetically united to their reci-
pients, by which luting will be altogether unne-
ceflaiy.

OF CHEMISTRY. 491

CHAP. VIII.

Of Operations upon Comhujiion and Deflagratron.

SECT. I.

Of Combujlion in General.

COMBUSTION, according to what has
been already faid in the Firft Part of this
Work, is the decompofition of oxygen gas pro-
duced by a combuftible body. The oxygen
which forms the bafe of this gas is abforbed by,
and enters into combination with, the burning
body, while the caloric and light are fet free.
Every combuftion, therefore, neceflarily fuppo-
fes oxygenation ; whereas, on the contrary,
every oxygenation does not neceflarily imply
concomitant combuftion ; becaufe combuftion,
properly fo called, cannot take place without
difengagement of caloric and light. Before
combuftion can take place, it is neceflary that
thiB bafe of oxygen gas Ihould have greater affi-
nity

ELEMENTS

iiity to the combuftLble body than it has to ca*
loric ; and this eleAive attradion, to uCc Berg*
-niati\ cxprefllon, can only take place at a certam
degree of temperature, which is different for eack
combultiblc fubllance ; hence the neceflity of gi-
ving a firll motion or beginning to every comr
bullion by the approach of a heated body. Thii
iicccllity of heating any body we mean to bum
tlcpctids upon certain confiderations, which have
i]ot hitherto been attended to by any natural
pbiloliipher, wherefore I fhall enlarge a little
upon the fubjeA in this place.

Nature is at prefent in a ftate of equilibrium,
which cannot have been attained until all the
rpontuncous combuftions or oxygenations pof-
Itble in the ordinary degrees of temperature had

OF tHEMISTRY. 493

known to chemiftry. By gradually 'increafing
the temperature of the earth .the fame circum-
ftance would fucceffively happen to all the bo-
dies capable 43f combuftion ; and, at lafty every
poffible combuftion having taken place, there
would no longer exift any combuftible body
whatever, as every fubftance fufceptible of that
operation would be oxygenated, and confequent-
ly incombuftible.

There cannot therefore exift, fo far as relates
to us, any combuftible body, except fuch as are
incombuftible in. the ordinary temperatures of
the earth ; or, what is the fame thing, in other
words, that it is eflential to the nature of every
combuftible body, not to poflefs the property of
.combuftion, unlefs heated, or raifed to the de-
gree of temperature at which its combuftion na-
turally takes place. When this degree is once
produced, combuftion commences, and the calo-
ric which is difengaged by the decompoQtion of
the oxygen gas, keeps up the temperature ne-
ceflary for continuing combuftion. When this
is not the cafe, that is, when the difengaged ca-
loric is infufficient for keeping up the neceflary
temperature, the combuftion ceafes : This cir-
cumftance is exprefled in common language
by faying, that a body burns ill, or with diffi-
culty.

Although combuftion poflefles fome circum-
ft ^ccs in common with diftillation, efpecially

with

494

EL£M£NTS

vri:h the csmpound kind of that operation, thcj
dioer io a very nuterial poiDt. In diftiUatios
there is a feparadon of one part of the elcmaKs
of the fubtlaoce from each other^and a confeqneit
cozibinatioQ of thefe, in a new order, occafionej
by the affinities which take place in the increafd
teraperdture produced during diftillation : Tlu
likeniie happens in combu^on, but with thii
farther circumftancc, that a new element, not
originally in the body, is brought into adtion;
oxygen is added to the fubftance fubmitted to
the operation, and caloric is difengaged.

The necelBty of employing oxygen in the
flate of gas in all experiments with combuftioEh
and the rigorous determination of the quanti*
ties employed, render this kind of operatioai
pecuViarly troublefome. As almoft all the pro- |

OF CHEMISTRY. 495

nature of the combuftible bodies, but upon that
of the ioftruments neceflary for combuftiou.']

SECT. 11.
Of ibe Comhu/lion of Pbojpborus.

In thefe combuftipps we 'begin by filling a jar,
capable at leaft of holding fiic pint$, with o^y-
f^ gas la the water appajratus, PI. V. Fig. i. ;
. when it is perfedly fuU, fo that the gas begins
to flow out below, the jar A is carried to the
vnercury apparatus, PI. XV. Fig. 3. We then
i^ry the furlace of the mercury, both within and
without the jar, by me^ns of blotting-papeiv ta-
king care to keep the paper for fome time en-
tirely immerfed in the 'mercury before it is in-
troduced under the jar, left we let in any com-
mon air, which fticks Tery obftinately to the
furface of the paper. Thq body to be fubmit-
ted to combuftion, being firft very ^accurately
weighed in nice fcaks, is placed in a fmall flat
Iballow dUb» D, of iron or porcelain ; this is
covered by the larger j:up P, which ferves the
office of a diving-bell, aikd the whole is pafled
through the mercury into the jar, after which
the larger cup is retired.. . The difficulty of paf-
(ing the materials of combuftion in this manner

through

Et£llENT S

fc^mmj wj be sroided by raifin^
^ fiis «f the jtr. A, for a raomoi^
1^ ■ Ac itde cap, D. with the com-
wig, » qoddy u polfible. In this
'ifBan^ 8 finall quantity of com- '
pm mm the jar, bat it is fo very ia<
kaaat to injare either the progtcfi
f W tbc experinient io %uy fenJibli

VknAe mp, D, is introduced under the
jK. «cAc&out a part of the oxygen gas. Co ai
■aiuufc Ac mercury to E F, as formerly dire<fte(i
; Hod. Ck^ V. olheiwife when the combuf-
Mrfea47 i* fet on fire, the gas becoming di-
0i would be in part forced out, and we (bould
• koger be able to make any accurate calcu-
non of the quantities before and after the ex-
periment. A very convenient mode of draw-
ing out the air is by means of an air-pump fy-
ringc adapted to tlie fyphon, G H I, by which
the mercury may be raifcd to any degree under
twenty-eight inches. Very inflammable bodies,
sphofphorus, are fet on fire by means of the
I crooked iron wire, M N, PI. IV. Fig. i6. made
ted hot, and pafled quickly through the mercu-
ry. Such as are lefs eafily fet on fire have a
finali portion of tinder, upon which a minute
IKtklc of pholphorus ^is fixed, laid upon them
gic ufing the red hot iro"

/

OF CHEMISTRT. 497

In the firft moment of combuftion the air, be-
ing heated, rarifies, and the mercury defcends ;
but when, as in combuilions of phoTphorus and
iron, no elaftic fluid ia formed, abforption be-
comes prefently very fenOble, and the mercury
rifes high into the jar. Great attention mu(t be
ufed not to burn too large a quantity of any Tub-
ftance in a given quantity of gas, otherwife, to-
wards the end of the experiment, the cup would
approach fo near the top of the jar as to endan-
ger breaking it, by the great heat produced, and
the fudden refrigeration from the cold mercury*
For the methods of meafuring the volume of the
gaffes, and for correding the meafures according
to the height of the barometer and thermometer,
&c. fee Chap. II. Seft. V. and VI. of this Part.

The above procefs anfwers very well for burn-
ing all the concrete fubftances, and even for the
fixed oils : Thefe laft are burnt in lamps under
the jar, and are readily fet on fire by means of
tinder, phofphorus, and hot iron. But it is dan-
gerous for fubftances fufceptible of evaporating
in a moderate heat, fuch as ether, alkohol, and
the eflential oils ; thefe fubftances diflblve in con-
fiderable quantity in oxygen gas j and, when fet
on fire, a dangerous and fudden explofion takes
place, which forces up the jar to a great height^
and daihes it in a thoufand pieces. From the
•flTefts'of two fuch explofions fomc of the mem-

I i ber^

raped- ^^^|
ler of ope^l

49S ELEMENTS

bers of the Academy and myfelf cfcaped- '
narrowly. Bcfides, llioiigh this manner of ope-
rating is fufficieiit for determining pretty accu-
rately the quantity of oxygen gas ablbrbcd, and
of carbonic acid produced, yet as water is Hkewife
formed in all experiments upon vegetable and
animal matters which contain an cxcefs of hydro-
gen, this apparatus can neither coUecl it, nor de-
termine its quantity. The ex.periment with phof-
phorus is even incomplete in this way, as it is Jm-
polfible to demonllrate that the weight of the
phofphoric acid produced is equal to the fum of
the weights of the phofphorus burot and of oxy-
gen gas ablbrbed during the procefs: I have been,
therefore, obliged to vary the inftruments accord-
ing to circumllanccs, and to employ feveral of dif-
fcrent kinds, which I fhall defcribe in their order,
beginning with that ufed for burning phofphorus.
Take a large balloon A, PI. IV. Fig. 4. of cry-
ftal or white glafs, with an opening, EF, about
two inches and a half, or three inches, diame-
ter, to which a cap of brafs is accurately fitted
with emery, and which has two holes for the
paffage of the tubes .v ,v x, yyy. Before (hutting
the balloon with its cover, place within it the
Hand, BC, fupporting the cup of porcelain, D,
which contains the phofphorus. Then lute on
the cap with fat lute, and allow it to dry for
fome days, and weigh the whole accurately

r

.>

OF CHEMISTRY. 499

afte^ this exhaufl the balloon by meand of an
air-pump conneded with the tube xx x, and fill
it with oxygen gas by the tube y yy^ from the
gazometer, PL VIII. Fig. i. defcribed Chap. IL
Sedt. 11. of this Part. The Pholphorus is then
fet on fire by means of a burning^glafs, and is aU
lowed to bum till the cloud of concrete phofpho-
ric acid flops the combuflion, oxygen gas being
continually fupplied from the gazometer. When
the apparatus has cooled, it is weighed and un-
luted i the tare of the inftrument being allowed^
the weight is that of the phofphoric acid contain-
ed. It is proper, for greater accuracy, to exa-
mine the air or gas coQtained in the balloon after
combuflion, as it may happen to be fomewhat
lieavier or lighter than common air ; and this
difference of weight muft be taken into account
in the calculations upon the refults of the expe«
riment«

I
I

SECT. IIL

Of tbe Combiifiion of CbarcoaU

apjj^aratus I have employed for this pro-

y fmall conical furnace of ham-

rcfented in perlpedlive, PL XII.

ally difplayed Fig. 11. It is

I i ^ divided

498

bcrs of the

. A8C, where tlKcte

Darrowly.

<(. aod the a&i-hik

nliog is {ui^i

i^ iBiddle of the dam

rudjr the 4U<u.

_9X3> u lutxixluce the rbwoai

ofiaikoaiuijl

^^^^•:Mtytag oS the air v^ad

finned m iW

^^^iJtHM. Vluaugh tbe nfaq

MJillJ MlUijj

^^^Matci. witb the guxofDenv

go.d»frf|

Ka.iK. wwrM ^ fuppoctni

vx^uxiaqm

(^•MHVAl >M» the afli-hok

pfeorasberen

,^ nwiitt ^ Hf application d

fafibfetadcr

, .^i»_i*.i*«, «k pa<) through Um

pki^rioric.

tbevrig^

'^iWfc

gEH!r.--^>>

•- -nrts of atmo

*cr

.- .tcidgas du>

■«•

Mio the axoiM

far

%xica» altei

tor

»rt^tenc air

T.

. .^ ^a azobc g«

Cdcokit

, MiAmre CO patt o4

t*v tacfce*

.._ > !Jle chimney, GH,

lot.:. :'■-

.-„ 4, uai csriTerf tile ga

Wi-.

4. -vlix loludoa of ca«^

f««*E--;

^ «i <» - 4ii^

■J <£«»•» I

OF CHEMISTRY.

501

its lower end S, refts upon the grate, d f, which
it occupiea entirely ; in the next place, the fur-
nace is filled with charcoal, and the whole is
weighed again, to know the exaA quantity of
charcoal fubmitted to experiment. The furnatc
is now put in its place, the tube, Im «, is fcrew-
ed to that which communicates with the gazome-
ter, and the tube, op, to that which communi-
cates with the bottles of alkaline folution. Every
thing being in readinefs, the ftop-cock of thega-
zometer is opened, a fmall piece of burning
charcoal is thrown into the tube, RS, which is
inftantly withdrawn, and the tube, 0 f>, is fcrew-
ed to the chimney, GH. The little piece of
burning charcoal fails upon the grate, and in this
manner gets below the whole charcoal, and is
kept on fire by the ftream of air from the gazo-
meter. To be certain that the combuftion is be-
gun, and that it goes on properly, the tube, tj rs,
is fixed to the furnace, having a piece of glafs
cemented to its upper extremity s, through which
- we can fee if the charcoal be on fire.

I negleded to obfcrve above, that the furnace,
and its appendages, are plunged into water in the
ciftern, TVXY, Fig. 11. PI. XII. to which ice
may be added to moderate the heat, if necelTarj ;
though the heat is by no means very condder-
able, as there is no air fupplied but what comes
from the gazometer, and no more of the charcoal

Ii3

burns

50*

ELEMENTS

burns at one time than what ia immediatelj om
the grate.

As one piece of charcoal is conrumed, another
falls down into its place, in confequence of the
declivity of the fides of the furnace; thi» gets in-
to the ftream of air, from the grate, d e, and it
burnt ; and fo on, fucccffiTcIy, till the whok
charcoal is confumcd. The air which haa ferveil
the purpofe of the combuftion pafles through the
mafs of charcoal, and is forced, by the preflun
of the gazoraeter, to efcape through the tub^
0 Py and to paft <through (be bottles of alkaline
iblutiun.

This experiment furnilhes all the neceflaiy
data for a complete analyfis of atmofphcric air
and of charcoaL We know the weight of char-

OF CHEMISTRY. 503

In a future memoir I ihall give an account to
the Academy of a feries-crf experiments I have
undertaken^ with this iaftrument, upon all the
vegetable and animal charcoals. By fome very
(light alterations, this machine may be made to
anfwer for obferving the principal phenomena of
refpiratioa.

SECT. iV.

Of the Combuftion qf Oils.

Oils are more compound in their nature than
oharcoal, being formed by the combination of
at leaft two elements, carbon and hydrogen ; of
courfe, after their combuftion in common air,
w*ater, carbonic acid gas, and azotic gas remain.
Hence the apparatus employed for their combui^
tion requires to be adapted for coUeding thefe *
three produds, and is confequently more com-
plicated than the charcoal furnace.

The apparatus I employ for this purpofe is
compofed of a large jar or pitcher A, PL XII.
Fig. 4. furrounded at its upper edge by a rim of
iron properly cemented at DE, and receding
from the jar at BC, fo as to leave a furrow or
gutter XX J between it and the outlide of. the jar,

I i 4 fomewhat

504

EL EMI NTS

ibmewhat more thAitvo incites ^ecp» Thsc^

TCT or Udoftbejti^Fig.S-i>Ul£ewifefiKnMHl>
ed by an iron rim/^.vhich bdjufts into ^
gutter X X, Cig. 4. whleb^ being filled with ma-
cury, has the cffeft of dafiag the jar benMilt
call;y io an ioftant,' wichovt sliag anj late ; Mit
as the gutter will hold about two jocbe^ of am*
cury. the air in the jar may. be made to fufiai
the prefliire of more than two feet of wate;
wi:hout danger of in efci^iipg.

The lid has foor holes, Tbik, for the paflaf
of an equal number of tubes. The opeoing T
is furnifhed with.. « lilhsi box, through whidt
palTes the rod. Fig. 3. intended for nuGog ml
lotrering the wick bf ^ lamp, as wiU be after-
wards dire^d. Tfa« iJuee other hols we m-
tended for tin: paffage of three fgvenil

OF CHEMISTRY. 505

the refervoir one way or the other, it is made to
life or i^ll, by which the oil is kept at the necef-
fary level.

When the fyphon is to be filled, and the com-
munication formed between the refervoir of oil
and the lamp, the ftop-cock c is (hut, and that
at f opened ; oil is then poured in by the open-
ing/at the top of the fyphon, till it rifes within
three or four lines of the upper edge of the lamp,
after which the ftop^ock k is (hut, and that at c
opened ; the oil is next poured in at ^ till the
branch 6 ri^ of the fyphon is filled, and then the
ftop-cock e is clofed. The two branches of the
fyphon being now completely filled, a communi-
cation is fully eftablilhed between the reiervoir
and the lamp.

In PL XIL Fig. x. all the parts of the lamp
1 1, Fig. a. are reprefented magnified, to Ihew
them diilindly. l^e tube i k carries the oil
from the refervoir to the cavity aM4i a^ which
contains the wick ^ the tube 9, 10, brings the air
from the gaiomcfter for keeping up the combuf-
tion ; this air fpTeads through the czVityddddj
and, by means of the paflages c c c c and bbbb,
is dillribttted on each fide of the wick, after the
principles of the lamps conftrudled by Argand,
Quinquet, and Lange.

To render the whole of this complicated ap*
paratus more cafily underftood, and that its de-
fcription may make all others of the fame kind

more

OF CHEMISTRY. 507

main in folution, it is abforbed by deliquefcent
falts contained in the tube 19, 20.

All thefe precautions are folely intended for
colleding and determining the quantity of water
formed during the experiment ; the carbonic acid
and azotic gas remain to be afcertained. The
former is abforbed by cauftic alkaline folution in
the bottles 22 and 25/ 1 have only reprefented
two of thefe in the figure, but nine at lead are
requifite ; and thelaft of the ferie^ may be half
filled with lime-water, which is the moft certain
reagent for indicating the prefence of carbonic
acid ; if the lime-water is not rendered turbid,
we may be certain that no fenfible quantity of
that acid remains in the air.

The reft of the air which has ferved for com-
buftion, and which chiefly confifts of azotic gas,
though ftill mixed with a confiderable portion
of oxygen gas, which has efcaped unchanged
from the combuftion, is carried through a third
tube 28, 29, of deliquefcent falts, to deprive it
of any moifture it may have acquired in the
bottles of alkaline folution and lime-water, and
from thence by the tube 29, 30, into a gazo-
meter, where its quantity is afcertained. Small
eflays are then taken from it, which are expofed
to a folution of fulphuret of potafh, to afcertain
the proportions of oxygen and azotic gas it con-

tBins. rJr

In .the. combuftion of ^oUs the wick becomes

■mW ft.«v /MP/v»t^».tfi* ,^

I m

at

■

588 ELEMENTS

at lall cbarred, and obAru^s the rife of the «i;
bcBiIcs, if we raife the wick above a certae
lieight, more oil rifes through its capillary tubet
than the Ilream of air is capable of confuminL
and fmoke is produced. Hence is is necefiiu7
TO be able to lengthen or (horten the uick witt
out opening the apparatus ; this is accomplilb-
ed by means of the rod 31, 32, 33, 34, whid
pafTcf through a leather box, and is conne6ui
with the fupport of the wick ; and that the dm-
tion of this rod, and confcquently of the wid;
m*y be regulated with the utmolt fn]oothiM&
and facility, it is moTed at pleafure by a pinioi
which plays in a toothed rack. The rod, witb
its appendages, are reprefented PL XII. Fig. 3.
!t appeared to me, that the combuftion would be
affiled by furrounding the Same of the laap
with a fmall glal's }ar c^n at both ends, as n.
preteoted in its place in Pi. XI.

I fhatt not enter into a more detatted defec-
tion of the coDltrui^ion of this apparatus, which
is AiU capable of being altered and modified io
maoy rrfpefls; but Ihall only add, that wbeo it
h to be ufed in experiment, the lamp and refer-
Toir uith the contained oil muft be accuiacdy
weighed, after which it is placed as bcfisrc di-
rected, and hghted ; having then formed tbe
connexion between the air in the gaxoroeter
BiKi the Limp, the cxtt^/^^ A. PL XI. b &x-
t of the board-

OF CHEMISTRY. 509

#

B C, tuid by two rods of iron which conned this
board with the lid, and are fcrewed to it. A
fmall quantity of oil is burnt while the jar is ad-
jufting to the lid, and the produd of that cpm-
buftion is loft ; there is likewife a fxnaU portion of
air froni the gazoaieter loft at the fame time.
Both of thefe are of very inconfiderable confe-
quence in esteofive ^sptriB^ol^ wd th»f are
even capable of beiog mined in our calcuUtioti
of the refttlts.

In a particular memoir^ I fiitU give an aocounfc
to the Acadcnor of tho difficulties infc^airable
from this kind of exp«arinieQtt : Thefe are fo ia-^
furmountable and tfouUeibm^ that { have not
hitlierto been abk to fi^btaia any rigoi^ws^ deter*-
mi nation of tba quaiititks of the proda^. I have
fuffident proo^ however, tbat the fined oUa ara
entirely refolved dutiitg combuftioa into wat^r
and carbonic add gaSi and confeqaentj^y %hvt/
they are compofiul of hydrogen and caibon ^ bat
I have no certain kaowledge xei^ieAiag tfaa ff^
poctioes of thefe ingredimuts.

SECT.

ELEMENTS

SECT. V,

Of the Combujlion af Alkcbal.

The combuftion of alkohol may be very readi-
ly performed in the apparatus already defcribed
for the combuftion of charcoal and phoiphorus.
A lamp filled with alkohol is placed under the
jar A, PI. IV. Fig. 3. a fraall morfel of phof-
phorus' 13 placed upon the wick of the lamp,
which is fet on fire by means of the hot iron, as
before direfted. This procefs is, however, li-
able to confiderable inconveniency ; it is dan-
gerous to make ufe of oxygen gas at the begin-
ning of the experiment for fear of deflagration,
which is even liable to happen when commoD
air is employed. An accident of this kind bad
very near proved fatal to myfelf, in prefence of
■ fome members of the Academy. Inftead of prepa-
ring the experiment, as ufual, at the time it was
to be performed, I had difpofed every thing in or-
der the evening before ; the atmofpheric air of the
jar had thereby fufficient time to diflblve a'good
deal of the alkohol, and thi; evaporation had
even been confiderably promoted by the height
of the column of mercury, which I had raifcd.
toEF, PI. IV. Fig. 3. The moment I attempt-
ed

OF CHEMISTRY. 511

cd to fet the little morfel of phofphorus on fire
by means of the red hot iron, a violent explofion
took place, which threw the jar with great vio-
lence againft the floor of the laboratory, and
dafhed it in a thoufand pieces.

Hence we can only operate upon very fmall
quantities, fuch as ten or twelve grains of alko-
hol, in this manner ; and the errors which may
be committed in experiments upon fuch fmall
quantities prevent our placing any confidence in
their refults. I endeavoured to prolong the com-
buflion, in the experiments contained in the
Memoirs of the Academy for 1784, p-593. by
lighting the alkohol firft in common air, and fur-
nifhing oxygen gas afterwards to the jar, in pro-
portion as it confumed ; but the carbonic acid gas
produced by the procefs became a great hinder-
ance to the combuftion, the more fo that alkohol
is but difficultly combuftible, efpecially in worfe
than common air ; fo that even in this way very
fmall quantities only could be burnt.

Perhaps this combuftion might fucceed better
in the oil appartus, PI. XI, ; but I have not
hitherto ventured to try it. The jar A in whicti
the combuflioa is performed is near 1400 cubi-
cal inches in dimenfion ; and, were an explofion
to take place in fuch a veflel, its confequences
would be very terrible, and very difficult to
guard againft. I have not, however, defpairecj
^^ making the attempt.

In

Sii iTlkmznts

In confequence of thefe difficulties, I hiT:
been hitherto obliged to confine myfelf to eipe-
ricnents upon very ftnall quantities of alkobol, ti
leaft to combuftions made in open vellels, fuel
as ihat reprelenteJ in PI. IX Fig. 5. which wiH
be dcicribed in Sedion VII. of this Chapter. ]i
I am ever able to remove thefe difficulties, I Ssi
reCume ttiis inveiti^tion.

S Jt; C T. VI.
O/tbff Combttfiktt qfEtber,

Though the combuftion of ether in clofe Tcf-

OF GHEMfSTRT. 513

ibvcefl, by tke pri^it of the ganbiAttel*, to boil
up through the etiker ia the rdfervblr. Vfi
may replace the ethef iii this firft f efenhiiii, in
proportion as it is 4iflblVed and carried '6fF' by
the air, by means of the fupplMfehtarji^ reietN^
voir £, creniieded by af iivak tube fifteeti oi^
eighteen inches long, and ihut by a fttfj^-eodk';
Hiis len^h of the eOAneftirtg tube is to Wb^
tKt deibending ether toloirereome 1%e ieftftance^
occafioned by the prttlBRii^ of the air frbm'tbe gi^
tometer. .':.:.'

The air, thus loaded with y^^ottrs of Wht*,
is coilduiSled by the tube 5, 6, 7, 8; c>, to thd jar
A, into ^ich it is aUowed to efcape through a
capillary opening, at the extrcmrty "of which it is
fet on fire. The alir, whch it has fcrt^d the pur-
pofe of eombuftion, paffes through. the bottle 16,
PL XI. the worm 17, 18, and the dtliqiJefcent
tube 19, 20, after which it pafles through the al-
kaline bottles ; in thefe its carbonic acid gas is
abforbed, the water formed during the experi-
ment having been preyioufliy depofite^^in the
former parts of the apparatus.

When I caufed conftru6l this apparatus, I
fuppofed diat tbue pombki^lioor of-atmolphe^rif air
and etl^er fofimed in tbiBi refi^ir¥oir a A;cr/,< PI Xilh
Fig* ^ waa 10 proper .t^RoportiQafov.ibpportiiig
coQibiifttani but in tlii9 I wais ^miftakeo; fot
tbcrt IS a very confiderable quantity of excefs of
*ki|^fo that an additional quantity of atmo-
r K k ^heric

514

ELEMENTS

Ipheric air is necelTarj to enable it to burn fuUy,
Hence a lamp conAruded upon tliefe principles
wilt burn in the open air, which furaiOies the
quantity of oxygen ncceffary for combufliaa,
biit will not burn in clofe vciTcls in which the
air is not renewed. Owing to this circumilaiKC,
my ether lamp went out foon after being ligltf-
cd and (hut up in the jar A, PI. XI T. Fig. B.
To remedy this defeat, I endeavoured to bring
atCDofpheric air to the lamp by the lateral tubt
10, II, 13, II, 14, 15, which I diftributed ci^
culurly round the Hame ; but the Hame is fo ti-
eeedingly rare, that it is blown out by the gentled
poflible ftieam of air, fo that I have not hitherto
fucceeded in burning ether. 1 do not, however,
defpair of being able to accomptilb it by mean
of fome changes I am about to have made
this apparatus..

SECT. vn.

Of the Combtifthn tf Hydrogen Gas^ t
mathn of IVattr.

'Iff thfc fonnntion of water, two

hydrogen and oxygen, which are both
aeriform date before combuftion, are
ed<ia«CP'»''l(iUi<l, or water, by the opei

*3l> :. -jX^'io T'lTt .i

OF CHEMISTRY. 515

This experiment would be very eafy, axid would
only require very fimple inflrumepts, if it were
poflibLe to procure the two gafles perfeftly pure,
fo that they might bum without any refiduum.
We might, in that cafe, operate in very fmall
veffels, and, by continusilly furnifhing the two
gafles in proper proportions, might continue the
combuftion indefinitely, fiut^ hithetto^ chemifts
have only employed impure oxygen gas^ mixed
with azotic gas ; from which circomflance they
have only been able to keep up the combuftion
of hydrogen gas for a very limited time in clofe
veflels, becaufe^ as the refiduum of azotic ^as
is continually increafing, the air becomes at lad
fo much contaminated, that the flame weakens
and goes out. This inconvenience is fo much the
greater in proportion as the oxygen gas employ-
ed is lefs pure. From this circumftance, we
muft either be fatisfied with operating upon fmall
quantities, or muft exhauft the veflels at in-
tervals, to get rid of the refiduum of azotic
gas ; but, in this cafe, a portion of the water
formed during the experiment is evaporated by
the exhauftion ; and the refulting error is the
more dangerous to the accuracy of the proccfs,
that we have no certain means of afcertaining
its value.

Thefe confiderations make me defirpus to

repeat the principal experiments of pneumatic

*€K5^ry with oxygen gas entirely free from

K k 2 any

Si6

ELEMENTS

any admixture of azotic gas ; and this may be
procured from oxygenated muriat of potafb.
The oxygen gas exlraded from this fait docs
nor appear to contain aiol, iinlefs accidentally;
fo that by proper precautions, it may be ob-
tained perfeftly pure In the mean lime, tbt
apparatus employed by Mr Meufnier and dk
for the combuftion of hydrogen gas. which ii
defcribed in the experiment for recompofitioii
of water, Part I. Chap. VIII. and need not there-
fore be here repeated, will anfwer the purpofe;
when pure galles are procured, this apparatui
will require no alterations, except that the ca-
pacity of the veflels may then be diminithed. See
PJ. IV. Fi^. 5.

The combullion, when once begun, conti-
nues for a couGderabie time, bnl weakens gr»-
doally, in proportion as the quantity of azotic
gas, remaining from the combuftion, increajes
till iit laft the aiofic gas is in Aicb over proptff-
lion that the combullion can no longer be (ajf*
ported, and the dame goes out. This fpontft-
neous estindion mud be prevented, becaiife, m
the hydrogen gas is prefled npon in its refex-
voir, by an inch and a half of water, while the
oxygen gas fuffers a prelTurc only of three Unei^
a mixture of the two would lake place in ifac
balloon, which would ;tt 1^^^ forced, by ihr
fuperiorw|A||h into tj^^^kir of oxyn
gas : ^^[^^^Bk^ co^^^^^fi be I

OF CHEMISTRY. 517

pcd, by (hutting the ftop-cock of the tube d Dd
whenever the flame grows very feeble ; for which
purpofe it muft be attentively watched.

There is another apparatus for combuftion,
which, though we caanoC with it perform expe^^
riments with the fame Scrupulous exm^lnefs as
with the preceding inftruments, gives very ilri-
king refults, that are extremely proper to be
/hewn in courfes of pfailofophical chemiftry. It
confifts of a worm £F, Fl. IX. ^ig. 5. contained
in a metallic cooler ABCD. To the upper part
of this worm J^ the chimney CH is fixed, which
is compofed q£ two tubes, the inner of which is
a continuation of the worm, and the oi^ter one is
a cafe of tin>plate, which furrounds it at about
an inch diftance, and the interval is fil}ed up with
fand. Ac the inferior extremity K of the inner
tube, a glafs tube is fixed^ to which we adopt the
Argand lamp LM for burning alkohol, &c.

Things being thus difpofed, and the lamp

being filled with a determinate quantity of alko^

hoi, it is fet on fire ; the water which is formed

during the combuftion rifes in the chimney KE,

and being condenfed in the worm^ n|QS out at

its extremity F into the bottle P. The double

tube of the chimney, filled with fand in the in-

terilice, is to prevent the tube from cooling in

ito ,UAper part, and condenfing the water ; o-

ii It would fall back in the tube, and we

"f.be able to a(certain its guantity^ and

^ k 3 btfides

OF CHEMISTRY- ^xp

becomes difengaged in its free itate; but, as
this difengagetnent, wben made iii common air»
is flow and progreffive, it is fcac^efy' e^vident to
the fenfes. It is quite o€herwife,liowev«r, when
oxydation takes place in oxygen gas ; fof^ beis^
produced with much greater rapidity, it is ge»
tiecally accompanied with heat and light, fo as
evidently to (hew that metallic fubftances are
real combuftible bodies. ^ ^

All the metals have not the iame degree of
affinity to oxygen. Gold, iilver, and platina^ for
inftance, are incapable of taking it away from
its combination with caloric, even in tho'greateft
known heat; whereas the other metals abforbit
in a larger or fmaller quantity, until the affinities
of the metal to oxygen, and of the latter to calo-
ric, are in exad equilibrium.* Indeed, ^his ftate
of equilibrium of affinities may be turned is a
general law of natare in all combinations* : : q
In all operations of this nature, the oxydation
of metals is accelerated by giving, free acceftid
the air ; it is fometimes much affifted by joining
the adion of bellows, fo contrived as todireft o
ftream of air over the furface of the metaL This
procefs becomes greatly more rapid >if a ftream
of oxygen gas be ufed, which is readily *done by
mcians of the gazometer formerly jdefcribod. The
metal, in this cafe, throws out a iihUiaiit fiame^
4 the ozydation is very quicklyracoompUflaed}
7. Kk4 but

5?o ELEMENTS

but this method can otily he ufcd ia very etc-
fined experimchls, on account of the expenceoi'
procuring oxygen gas. In the eflay of ores, aod
in ill the common operationa of the laborattay,
the culcination or oxydation of metals is uiiiaUj
pefformed in a difh of baked clay. PI. IV. fig,
6. coromoniy called a roafling '</', placed in i
ftrong furnace. The fubftanccs to be oxydald
are frequently ftirred, onpurpofcto prefent ftdli
furfiices lo the air.

Whenever this operation is performed uponi
metal which is not volatile, and from which Ro-
thiiig flies off into the furrounding air during the
proccTs, the metal acquires additional iveight ;
but the caiife of this increafcd weight durioc
oz-xdation could never have been difcovercd b;
meliis of exjieriments performed in free air;
and It is only ftnce thefe operations have been
perfosmed io clofe velfels, and in determioitte
quantities of air. that any jult conjectures have
been formed concerning the caufe of this pheim-
menon. The firft method for this purpofe is doe
to Dr Priertlcy, who expofes the metal to be cal-
cine in a porcelain cup N, PI. IV. Fig. 1 1. pift-
ced upon the Hand IK, under a jar A,
baX'on BCl

OF CHEMISTRY.

©sydation takes place, a pan of the oxygen con-
tained in the air combines with the metal, and a
proportional diminution of the volume of air is
produced ; what remains is nothing more than
azotic gas, flill however mixed with afmall quan-
tity of oxygen gas. I have given an account of a
feries of experiments made with this apparatus in
my Phylical and Chemical Eflays, firft pubUlhed
in 1773. Mercury may be ufed inrtcad of water
in this experiment, whereby the refults arc ren-
dered ftill more conclulive.

A.nolher procefs for this purpofe was invented
by Mr Boyle, and of which I gave an account
in the Memoirs of the Academy for I774»
p. 351. The metal is introduced into a retort,
PI. III. Fig. 30. the beak of which is hermeti-
cally fealed ■, the metal is then oxydated by
means of heat applied with great precaution.
The weight of the veflel. and its contained fub-
ftanccs, is not at all changed by this procefs,
until the extremity of the neck of the retort is
broken ; but, when that is done, the external
air rufhes in with a hilling noife. This opera-
lion is attended with danger, unlefs a part of
the air is driven out of the retort, by means of
lieat, before it is hermetically fealed, as other-
wife the retort would be apt to burft by the di-
lation of the air when placed in the furnace.
The quantity of air driven out may be received
Under a jav in the pneumato-chemical appara-
tus.

e- ELEMENTS

■XMs, by which its quantity, and that of the «r
'remaining in the retort, is afcertained. I haie
not multiplied my experiments upon oxydatioti
of metals fo much as I could have wifhed ; ori-
ihcr hare I obtained fatisfactory refults with any
metal except tin. It is much to be wilbed that
foiae pcrfuD would undertake a feries of expeti-
menu upon the oxydation of metals in the fevc-
ral gafles ; the fubjeft is important, and wouU
fully repay any (rouble which this kind of expe-
riment might occafion.

As all the oxyds of mercury are capsble of
reviTifying without addition, and reftore the
oxygen gas they bad before abforbed, this
feemed to be the mod proper metal for beco*
ming the fubjed of conclulive experiments up-
on OKvdation. I formerly endeavoured to ac-
complifh the oxydation of mercury in clofe vet
iels, by filling a retort, cont^^ining a fmall qutlt-
tity of mercury, with oxygen gp.s, and adaptiog
a bladder half full of the lame gas to its beak;
See PI. IV. Fig. 12. Afterwards, by heatiag
the mercury in the retort for a very long time,
I fucceedcd in oxydaling a very fmall portion,
fo as to form a little red oxyd floating upon the
furface of ihc running mercnrj- ; but the quan-
tity was fo fmall, that the fmaileil error com-
mitted in the determination of the quantities of
oxygen gas befiMMMAiafter the operation, muft
farown^^^^Bl' unccrtfiintjcjuoQ the
:fttlcs

OF CHEMISTRY. 525

rcfalts of the experiment. I was, befides, dif-
fatisfied with this procefs, and not without caufe,
left any air might have efcaped through the pores
of the bladder, more efpecially as it becomes ihri-
veiled by the heat of the furnace, unlefs covered
over with cloths kept conftantly wet.

Thi$ experiment is performed with more cer-
tainty in the apparatus defcribed in the Me-
moirs of the Academy for 1^75, p. 580. This
confifts of a retort. A, PI. IV. Fig. 2. having a
crooked glafs tube BCD£ of ten or twelve lines
internal diameter, melted on to its beak, and
which is engaged under the bell-glafs FG,
ftanding with its mouth downwards, in a bafon
filled with water or mercury. The retort is
placed upon the bars of the furnace MMNN,
PI. IV. Fig. 2. or in a fand-bath, and by means
of this apparatus we may, in the courfe of feve-
ral days, oxydate a fmall quantity of mercury in
common air ; the red oxyd floats upon the fur-
face, from which it may be coUe^ed and revived,
fo as to compare the quantity of oxygen gas ob-
tained in revivification with the abforption which
took place during oxydation. This kind of expe-
riment can only be performed upon a fmall fcale,
fo that no very certain conclufions can be drawn
from it*.

The

. t * S^ an dccaaiif, of this experimcnti Part I. Chap.
••• .

SM

ELEMENTS

Tbe combuftioa of iron in oxygen gas heof
A true osydation of that metal, ought to be
raenlioned in this place. The apparatus em-
ployed by Mr Ingcnhoul'i for this operatiou it
reprefented In PI. IV. Fig. 17, ; but, having^
ready defcrlbcd it fufficiendy in Chap. HI. I
fliall refer tbe reader to what is laid of it in thai
place. Iron maylikewife be oxyiUited by com-
bullion in veflels filled with oxygen g;is, in tit
way already direded for phofphorus and chai-
coal. This apparatus is reprefented PI. IV.
Fig. 3. and delciibed in the fifth chapter of the
firft part of this work. We learn from Mr Id-
genhoufz, that all the metals, except gold, fil-
ver, and mercury, may be burnt or oxydated in
the fame manner, by reducing them into very
iinc wire, or very thin plates cut into narrow
Hips ; thefe are twilled round with iron-wire,
which communicates the property of burning to
the other metals.

Mercury is even difficultly oxydated in free
air. In chemical laboratories, this procefs is U-
fually carried on in a matrals A, Fl, IV. Fig. tc.
having a very flat body, and a very long neck
BC, which veflel is commonly called BoyWs
Jbtll. A quantity of mercury is introduced fuf-
ficient to cover the bottom, and it is placed in
a fand-bittb. which ke^M^n a conHant heat
upprou|ifln|p that ^^1^^^ mercury. By
corn"

OF CHEMISTRY. 523

lar matraflfo during fevend montfas, and renew-
ing the mercury front time to time, a few oun-
ces of red Qxyd are at laft obtained. The great
flownefs and inconvenience of this apparatus a-
rifes from the air not being fufliciently renewed )
but if, on the other hand, too free a circulation
were given to the external air. It would carry oflf
the mercilty in folution in the ftate of vapour^
fo that in a few days none would remain la the
vcffel.

As, of all the experiments upon the oxydation
of metals, thoie with mercury;^are the mod con<»
clufive, it were much to be wifhed that a (imple
apparatus could be contrived by which this oxy*
dation and its refults might be demonftrated in
public couries. of chemiilry. This might, in my
opinion, be. accompliflied by methods fimilar to
thofe I have already derccibed for the combuftion
of charcoal and the oils ; but, owing to other
purfuits, I have not been able hitherto to refumc
this kind of experiment*

The oxyd of mercury revives without addi-
tion, by being heated to a (lightly red heat. In
this degree of temperature, oxygen has greater
affinity to caloric than to mercury, and forms
oxygen gas. This is always mixed with a fmall
portion of azotic gas, which indicates that the
mercury abforbs a fmall portion of this latter
gas during oxydation. It almofl: always con*
"^ns a little carbonic acid gas, which muft un*

doubtcdly

556

eli:m£nts

(loubtedly be attributed to the foulnefles of Ac'
osyd ; thefe are charred by the heat, and con-
vert a part of the oxygea gas into carbonic >•
tid.

, If chemifts were reduced to the neceffity of
procuring all the oxygen gas, employed in their
experiments. From mercury oxydated by bat
without addition,'or, us it is called, calcined «t
precipitated per fe, the exceffive deameis d
that preparation would render experiments, ctbi
upon a moderate fcalc, quite impra^icabk.
But mercury may likewil'e be oxydated by
means of nitric acid; and in this way wc pro-
cure a red axyd, even more pure than that pro-
duced by cilcination. I have ibmetimes pre-
pared this dxyd by diflblviog mercury in nitric
acid, evaporating to drynet's, and calcining the
fait, either: in a retort, or in capfules formed
of pieces of broken matraOes and retorts, ia.
the manner tbrmerly delcribed ; but I have ii6>
ver fucceeded in making it equally beautiM
with what is fold by the druggilb, and whkh
is, I believe, brought from Holland. In choof-
ing thib, we ought to prefer what is in lolid lumpi
compofed of foft adhering fcales, as when
powder it i* fometimes adulterated uit!
oxyd of lead.
To

lumpi
lenifcj

m

OF C H E M I S T'RflT. 5^.

«

^yhicfa is engaged under jars in tbe water pAeih-t
mato-chemical apparatus ; and I place a bottle '
in tbe water, at tbe end of the tube, for recei-
ving tbe mercury, in proportion as it revives and
difiils over. . As she oxygen gas never appears
till the retprt become^ redv it feems to prove the
principle eftabKftied by Mr BertboUet, that an
obfcure heat cai^ never form oxygen gas, and-
that light is one of its conftitueat elements. We
muft rejeA the firft portion of gas which comes
over, as being mixed with common air, from
what was contained in the retort at the begin-
ning of the experiment •, but, even with this pre-
caution, the oxygen gas procured is ufually con-
taminated with a tenth part of azotic gas, and
with a very fmall portion of carbonic acid gas*
This latter is readily got rid of, by making the
gas pafs through a folution of cauftic alkali, but
we know of no method for feparating the azotic
gas ; its proportions may however be afcertained,
by leaving a known quantity of the oxygen gas
contaminated with it for a fortnight, in contaA
with fulphuret of foda or potalh, which abforbs
the oxygen gas, and converts the fulphur into
fulphuric acid, leaving the azotic gas pure.

We may likewife procure oxygen gas from
black oxyd of manganefe, or from nitratof potafli,
by expofing them to a red heat, in the appara-
tus already defcribcd for operating upon red

oxyd

Sa>

ELEMENTS

oxTd of mercaxj ; oalj, m it lequires frtdi «
beat as is at leaft capable of Ibftening S^^ *b
muftemplojrecorttof ftoneorof porcdain. Bat
the pozeft aod beft ax^cn gas is what ia dififr
gaged from oxygenated nuiriatofpocaib by fia^
heat. This operatiMi is perfbniied ia a glafi le*
ton, and the gas obtaioed is peiftdly pmwK, jn-
Wded that the fiift poctions, wfaicb are nani
vith the conunoa air of the nffels, be iijiflrf

OF CHEMISTRY. 529

.1

CHAP. IX.

Of Deflagration.

Have already fliewn, Part I. Chapter IX.
that oxygen docs not always part with the
whole of the caloric it contained in the ftate of
gas, when it enters into combination with other
bodies. It carries almoft the whole of its caloric
along with it on entering into the combinations
which form nitric acid and oxygenated muriatic
acid ; fo th^t in nitrats, and more efpecially in
oxygenated muriats, the oxygen is, in a certain
degree, in the ftate of oxygen gas, condenfed,
and reduced to the fmalleft volume it is capable
of occupying.

In thefe combinations, the caloric exerts u
conftant adion upon the oxygen to bring it
back to the ftate of gas ; hence the oxygen ad-
heres but very flightly, and the fmalleft addi-
tional force is capable of fetting it free ; and,
when fuch force is applied, it often recovers the
ftate of gas inftantaneoufly. This rapid paflagc
from the folid to the aeriform ftate is called de-
tonation, or fulmination, becaufe it is ufually
accompanied with noife and explofion. Defla-
grations ^re commonly produced by means of
combinations of charcoal, either with nitre or

L 1 with

533

ELEMENTS

with oxygenated martat of potalh ; fometimcSrto
afliU the inflammation, fulpbur is added; aod,
upon the juft proportion of thefe ingredients, and
the proper manipulation of the mixture, tbe an
of making gun-powder depends.

As oxygen is changed, by deflagration wiA
charcoal, into carbonic acid, inltead of oiygin
gas, carbonic acid gas is difeiigaged, at Uall
when the mixture has been made in juft propor-
tions. In deflagration with nitre, azotic gas ii
likewife difengaged, becaufe azot is one of Uk
conditueut elements of nitric acid.

Tbe fudden and indantaaeous direngagemeot
and cxpanlion of thefe gafles is not, however,
I'ufEcient for explaining all the phenomena of de-
flagration ; becaufe, if this were the fole open-
ting power, gun-powder would always be fo mucli
the ftronger in proportion as the quantity of gai
difengaged in a given time was the more coati-
derable, which does not always accord with ex-
periment. I have tried fome kinds which produ-
ced alraoft double the effect of ordinary gun-
powder, although they gave out a fixlh partlcS
of gas during deflagration. It would appear that
the quantity of caloric difengaged at the moineut
of detonation contributes confiderably to theex-
panfive effedls produced ; for, although caloric
■ penetrates freely through the pores of every body
in nature, it can only do fo progreflively, and io
a given time ; hence, when the quantity difenga-
ged

OF CHEMISTRY. 531

ged at once is too large to get through the pores
of the furrounding bodies, it muft neceiTarily ad:
in the fame way with ordinary elailic fluids, and
muft overturn every thing that oppofes its paf-
fage. This muft, at leaft in part, take place
when gun- powder is fet on fire in a cannon j as,
although the metal is permeable too caloric, the
quantity difengaged at once is too large to find
its way through the pores of the metal, it muft
therefore make an efibrt to efcape on every fide ;
and, as the refiftance all around, excepting to-
wards the muzzle, is too great to be overcome,
this efibrt is neceflarily employed for expelling
the bullet.

The caloric produces a fecond effed, by
means of the repulfive force exerted between
its particles ; it caufes the gafles, difengaged at
the moment of deflagration, to expand with a
degree of force proportioned to the temperature
produced.

It is very probable that water is decompofed
during the deflagration of gyn-powder, and that
part ot the oxygen furniflied to the nafcent car-
bonic acid gas is produced from it. If fo, a
confiderable quantity of hydrogen gas muft be
difengaged in the inftant of deflagration, which
expands, and contributes to the force of the ex-
plofion. It may readily be conceived how great-
ly this circumftance muft increafe the effeft of
powder, if we confider that a pint of hydrogen

I^ 1 2 gRS

In Uie Uftl

.■ofcil wTOf ^^

deflagration of j,

the (late of gas, „,

tundred tiroes moc

Ihis circumftancc a

'yiotliecipIofiMl

I hove already

■^speriments upon t

•"Angspd during „

rt«coal and fulpi

likewife, .ill, n. „,

' liis method of inv

"cenrate condulio„s

"lent dementi of the
"l»i tefult, „f ,j,^,
eonfo,„c,Kj5 dnwn

'"■'Ij'lis of nitric acid
'°a.on of jv,e„„j„

"y foreign pbilofophe,

«■"' 1 l..re procured

OF CHEMISTRY. 533

employed. I would very carneftly advife fuch
as intend to repeat fome of thefe experiments^
to be very much upon their guard in operating
upon any mixture which contains nitre, char-
coal and fulphur, and more efpecially with thofe
in which oxygenated muriat of potaih is mixed
with thefe two materials.

I make ufe of piftol- barrels, about fix inches
long, and of five or fix lines diameter, having
the touch- hole fpiked up with an iron nail
ftrongly driven in, and broken in the hole, and
a little tin-fmith*8 folder run in to prevent any
poflible iflfue for the air. Thefe are charged
with a mixture of known quantities of nitre and
charcoal, or any other mixture capable of de»
flagration, reduced to an impalpable powder,
and formed into a pafte with a moderate quan-
tity of water. Every portion of the materials
introduced muft be rammed down with a ram-
mer nearly of the fame caliber witji the barrel,
four or five lines at the muzzle muft be left
empty, and about two inches of quick match
are added at the end of the charge. The only
difficulty in this experiment, efpecially when ful-
phur is contained in the mixture, is to difcover
the proper degree of moiftening ; for, if the
pafte be too much wetted, it will not take fire,
and if too dry, the deflagration is apt to become
too rapid, and even dangerous.

L I 3 When

•i-f-mm.' The

""« in the w«

"ft or more rapi,

'ure is more or le

S""on continue,.

"■^ 'ept fo„„,n,3j

vent the water fro

""! manner I hav<

PwdnceJ fro,,, ,^^

"'«'• or tivo ounces

'n >l"s manner oi

''«"n,i„e the quan

™8aged, becauli a

'"■""■WIepaffing

■carbonic acid i, ab

mains i and, jf ,j ^^

"■ra-niosIiaWfo
•^dcanea/il^determ

--"ft inonjedge „f
-«d by repeating,,,,,
■™«,«nd varying ,h,

OF CHEMISTRY.

535

I determine the weight of oxygen neceflary for
fatUTation, and deduce the quantity of oxygen
contained in a given weight of nitre.

I have ufed another procefs, by which the
refults of this experiment are confiderably more
accurate, which confifls in receiving the difen-
gaged gaffes in bell-glafles filled with mercury.
The mercurial apparatus I employ is large
enough to contain jars of from twelve to fifteen
pints in capacity, which are not very readily
managed when full of mercury, and even re-
quire to be filled by a particular method. When
the jar is placed in the ciftern of mercury, a
glafs fyphon is introduced, conneiJted with a
fmall air-pump, by means of which the air is
exhaufted, and the mercury rifes fo as to fill the
jar. After this, the gas of the deflagration is

I made to pafs into the jar in the fame manner as'
direded when water is employed.

I murt again repeat, that this fpecies of ex-
periment requires fo be performed with the
greateft poflible precautions. I have fometimes

I feen, when the difcngagement of gas proceeded
with too great rapidity, jars filled with more than
an hundred and fifty pounds of mercury driven
olVby the force of the explofion, and broken to
pieces, while the mercury was fcattcred about
in great quantities.

When the experiment has fucceeded, and the
is coUefled under the jar, its quantity in
L i 4 general.

536

ELEMENT S

general, snd the nature and quantities oF tbefe-
veral fpecies of gaffes of which the mixture ii
compofed, are accurately al'certained by the me-
thods already pointed out in the fecond chapter
of this part of my work. I have been preveat*
ed from putting the lad hand to the experi*
ments I had begun upon deflagration, from theit
connedtion with the objefts 1 am at prefent en-
gaged in; and I am in hopes they will throw
confiderable light upon the operations bclonff-
ing to the manufadlure of gun-powder.

OF CHEMISTRY. 537

CHAP. X.

Of the Injlruments necejfary for Operating upon
Bodies in very bigb Temperatures.

SECT. L

Of Fvfion.

WE have already feen, that hy aqueous fo-
lution, in which the particles of bodies
are feparated from each other, neither the fol-
vent nor the body held in folution arc at all de-
compofed ; fo that, whenever the caufe of re-
paration ceafes, the particles reunite, and the fa-
line fubftance recovers precifely the fame appear-
ance and properties it poflefled before folutioD«
Real folutions are produced by fire, or by in-
troducing and accumulating a great quantity of
caloric between the particles of bodies ; and this
fpecies of folution in caloric is ufually called /i/-
Jion.

This operation is commonly performed in
veffels called crucibles, which muft neceffarily

be

533

ELEMENTS

be lefs fufible than the bodies they are intended
to contain. Hence, in all ages, cheroifts hare
been extremely folicitous to procure cruciblei
of verj' refractory materials, or fuch as are ca-
pable of refifting a very high degree of hot
The befl arc made of very pure clay or of p«-
cclain earth; whereas fuch as are made of cliy
mixed with calcareous or Gliceous earth axe vert
fuiible. All the crucibles made in the neigfa-
bourhood of Paris are of this kind, and are coo-
fcquently unfit for mod chemical experimcnn.
The Heflian crucibles are tolerably good ; but
the bed are made of Limoges earth, which
fcems abfolutely infuGble. We have, in France^
a great many clays very fit for making cnici-
bles ; fuch, for iaftance, is the kind ufed for ma-
king raclting-pots at the glafs manufa«aory of Si
Gobin.

Crucibles are ntade of Tarious forms,
ding to the operations they are intended
form. Several of the mod common kii
reprefcntcd PJ. VII. Fig. 7, 8, 9, and
one reprefeuted at Fig. 9. is almoll fliut
mouth.

Though fufion may often take place w
changing the nature of the fufed body, tbi
ration is fre<iuenttyempIoyed as a chemical
of decompoling and recompoundjng bodie
this vrzj all the metals arc gjiJtracied from I
ores ; an^^]^ this ]

OF CHEMISTRY. 539

moulded, and alloyed with each other. By this
proce& fand and alkali are combined to form
glafs, and by it likewife paftes, or coloured ftones,
enamels, &c. are formed.

The adion of violent fire was much more fre-
quently employed by the ancient chemifts than
it is in modern experiments. Since greater pre-
cifion has been employed in philofophical re-
fearches, the bumid has been preferred to the
dry method of procefs, and fufion is feldom had
recourfe to until all the other means of analyfis
have failed.

SECT. II.

0/ Furnaces.

Thefe are inflruments of mod univerfal ufe
in chemiftry ; and, as the fuccefs of a great
number of experiments depends upon their be-
ing well or ill conftruded, it is of great impor-
tance that a laboratory be well provided in this
refpedt. A furnace is a kind of hollow cylindri-
cal tower, fometimes, widened above, PI. XIII.
Fig. I. ABCD, which muft have at lead two
lateral openings ; one in its upper part F, which

the door of the fire-place, and one below, G,

leading

ELEMENTS

leading to the alh-hole. Between ihefe the for-
nace is divided by a horizontal grate, intended
for fiipporting the fuel, the fiiuation of which
is marked in the figure by the line HI. Thoagfa
this be the leaft complicated of all the chemical
furnaces, yet it is applicable to a great number
of purpofes. By it lead, tin, bifimith, and, in
general, every fubftnncc which does not rcqaice
a very flrong fire, may be melted in crucibles;
it will ferve for metallic oxydations, for evapo-
ratory vefTels, and for fand-baths, as in PI. HI.
Fig. I. and 2. To render it proper for thcfe
purpofes, feveral notches, ta m m m, PL XIII.
Fig. I. are made in its upper edge, as otherwife
any pan which might be placed over the fire
would Hop the paflagc of the air, and prevent
the fuel from burning. This furnace can only
produce a moderate degree of heat, becaufe tlie
quantity of charcoal it is capable of confuming
is limited by the quantity of air which is allow-
ed to pafs through the opening G of the aih-
hole. Its power might be confiderably aug-
mented by enlarging this opening, but then the
great llreara of air which is convenient for foinc
operations might be hurtful in others ; where-
fore we muft have furnaces of different formi,
conftruded for different purpofes, in our labo-
ratories : There ought efpecially to be feveral
of the kind now d.efcfibcd of different Uzes.
.- "ioo'Wift* .- The

OF CHEMISTRY. 541

The reyerberatory furnace, PL XIII. Fig. 2,
is perhaps more neceiTary. This, like tjhQ com-
mon furnace, is compofed of the afli-hole HIK^L,
the fire-place: :K,LMN, the laboratory MNOP,
and the dom^ RRSS, with its funnel or chim-
ney TTVV ; and to this laft feveral additional
tubes may be adapted, according to tine nature
of the different experiments. The retort A is
placed in the.divifion called the laboratory^ and
is fupported by two" bars of iron which run a-
crofs the furnace, ..an4 its bes^ comes out at a
round hole infChe :6de of t^e. furnace, one half
of which is cut in the piece called the labora-
tory, and the other m the dome. In moft of
the ready madjp reverberatory furnaces which
are fold by the pottcirs at Paris, the openings
both above and below are too fmall : Xhefe do
not allow . a fufficient Vx^Iume of air to pa&
through ; hence,, as. the quantity of charcoai
confumed, on, %viiat|is much the fame thing,
the quantity of caloric difeogaged, is nearly in
proportion to the quantity of air which pafies
through the furnace, thefe furnaces do not

•

produce a fufficient effedt iii a great number of
experiments. To remedy this defe&, there
ought to be two openings GG to the afh-hole^
one of thefe is (hut up when only a moderate
fire is required ; and both are kept open when
the ftrongeft power of the furnace is to be
exerted. The opening of the dome SS ought

likewife

,4- ELEMENTS

Ukewife to be con6deraUy larger than it is nfb-
:il1y made.

It is of great importance not to em^o^ n
torts of too large fize in proportion to the fin-
nace, as a fufficient fpace ought always to be il-
lowed for the paQage of the air between tbe
fides of the furnace and the Teflel. The retort
A in the figure is too finall for the fize of tbe
furnace, yet I find it more eafy to point oitt die
error than to corred iL The- intention of tbe
dome is to oblige the flame aod heat to fumand
and llrtke back or reverherate upon ereiypKt
of the retort, whence the furnace gets tbe name
of rererbcratory. Without this circnunftuice
tbe retort would only be heated in its bottom,
the vapours raifed from the contained fubftance

OF CHEMISTRY. 543

influence of heat or of cold, while others are for
fuftaining the glafs, or forming a kind of fecond
retort, which fupports the glafs one during ope-
rations wherein the ftrength of the fire might
foften it. The former is made of brick-clay
with a little cow's hair beat up along with it,
into a pafte or mortar, and fpread over the glafs
or ftone retorts. The latter is made of pure
clay and pounded ftone-ware mixed together,
and ufed in the fame manner. This dries and
hardens by the fire, fo as to form a truQ fupple-
mentary retort capable of retaining the materials,
if the glafs retort below (hould crack or foften.
\But, in experiments which are intended for col-
lecting gafies, this lute, being porous, is of no
manner of ufe.

In a great many experiments, wherein very
violent fire is not required, the reverberatory
furnace may be ufed as a melting one, by leav-
ing out the piece called the laboratory, and
placing the dome immediately upon the fire-
place, as reprefcnted PL XIII. Fig. 3. The fur-
nace reprefented in Fig. 4. is very convenient
for fufions ; it is compofed of the fireplace and
afh-hole ABD, without a door, and having* a
hole E, which receives the muzzle of a pair of
bellows ftrongly luted on, and the dome ABGH,
which ought to be rather lower than is repre-
fented in the figure. This furnace is not ca-
pable of producing a very ftrong heat, but is

fufficient

5-M

ELEMENTS

fufficient for ordinary operations, and maybe
readily moved to any part of the labontoiy
where it is wanted. Though thefe particular
furnaces are very convenient^ every laboratioiy
mud be provided with a forge furnace, having k
good pair of bellows, or what is more neccffuy,
a powerful melting furnace. I fliall delcribe
the one I ufe, with the priacipica upon which it
is conftruded.

The air circulates lo a furnace in coniequeocc
of being heated in its paflage through the bulg-
ing coals ; it dilates, and, becoming lighter thao
the furrounding air, is forced to rife upwai^
by the prellure of the lateral columns o^oir,
and is replaced by frefli air from all fidea, tfy^
cially from below. This circulation o£ air
takes place uln:n coals :ire bunit

OF CHEMISTRY. 545

equal to AC, the one of cold air without, and
the other of heated air within the furnace,.
There muft be fome heated air above the open-
ing AB, and the fiiperior levity of this ought
likewife to be taken into confideration ; but, as
this portion is continually cooled and carried
off by the external air, it cannot produce any
great effedt.

But, if we add to this furnace a large hollow
tube GH AB of the fame diameter, which pre-
ferves the air which has been heated by the
burning coals from being cooled and difperfed
by the furrounding air, the difference of fpecific
gravity which caufes the circulation will then be
between two columns equal to GC, Hence, if
GC be three times the length of AC, the cir-
culation will have treble force. This is upon
the fuppofition that the air in GHCD is as
much heated as what is contained in ABCD,
which is not ftridly the cafe, becaiife the heat
muft decreafe between AB and GH ; but, as
the air in OHAB is much warmer than the ex-
ternal air, it follows, that the addition of the
tube muft increafe the rapidity of the ftream of
air, that a larger quantity muft pafs through
the coals, and coilfequently that a greater de«
gree of combuftion muft take plac^. •

We muft not, however, conclude front thefe
principles, that the length of this tube .ought to
be indefinitely prolonged ; for, fince the heat of

M m the

i: L E M K N 1' 9

the air gradually dimini(be6 in pafling from AB
to GH, even from the contact of the fides of the
tube, if the tube were prolonged to a certain
ilegrec, mx nould at lii!l come to a point where
the fpecific gravity of the included air would be
cqu4 to the air without; and, in this cafe, m
the cool air would no longer tend to rife up-
wards, it would become a gravitating mafs, re-
lilUng the afvenlion of the air below. Befides,
as this air, which h?s ferved for combullioa, is
Jiecellarily mixed with carbonic acid gas, which
is confidcrably heavier ihau common air, if the
tube were made long enough, the air might at
laft approsch fu near to the temperature of the
external air, as even to gravitate downwards ;
hence we muft conclude, that the length of the
tube added to a furnace muft have fome limit,
beyond which it weakens, infleadof ftrengthen-
ing, the force of the fire.

{'"rom thefe re|leiaious it follows, that the firft
foot of tube added to a furnace produces more
effect than the fixth, and the fixth more than
the tenth ; but we have no data to afcertaiii al
what height we ought to ilop. This limit of
ufeful addition is fo nuicli tlie farther in propor-
tion as the materials of the tube are weaker con-
duiilors of heat, becaufe the air will thereby he
io much lefs cookd ; hence baked earth is
much preferable to plate iron. It woul4
even of conrtqiance to make the lubcdoublflj

OF CHEMISTRY.

547

to fill ihe interval with rammed charcoal, which
is one of the worll known conductors of heat ;
by this the refrigeration of the air will be retard-
ed, and the rapidity of the flrcam of air confewa
quently increafcd ; and, by this means, the tubtl
may be made fo much the longer.

As the fire-place is the hotteft part of a fur-
nace, and the part where the air is moft dilated
in its paflage, this part ought to be made with a
confiderable widening or belly. This is the
more neceflary, as it is intended to contain tin.-
charcoal and crucible, a^ well as for the palfiigt;
of the air which I'upports, or rather producer
the combuftion ; hence we only allow the inter-
ftices between the coals for the palFage of the

From thefe principles my melting furnace is
conftrucled, which I believe is at kail equal in
power to any hitherto made, though I by no
means pretend that it poflcffes the greateft pof-
fiblc intenfity that can be produced in chemical
furnaces. The augmentation of the volume of
air produced during its palfage through a melt-
ing furnace not being hitherto afcertaiucd fiom
experiment, we are Qill unacquainted with the
' proportions which fliould exill between the in-
ferior and fuperior apertures, and the ahfolute
fixe of which thefe openings fhould be made is
rtill lefs underllood ; hence data are wanting
by which to proceed upon principle, and wo

M m 2

can

54* ELEMEKTS

em MD^aoceafMitbecad tn-«irw^iq»

i wh'Kh, according to the
Awed rafes, U in form of an elliptical fpbenri
it R^ne&ated FL XIIl. Fig. 6. ABCD ; it Ua
off at the two ends by two plain-^, which pifc
perpendicular to the axis, through the foa
the cUiptr. From this Qiape it is capable
containiDg a confiderable qiiaotity of charcoiL
uhile it leaves fui&cient fpace in the intcnJ
for the pit0~iige of tlie air. That no obftsl
may oppofc the free acccfs of external ait.il'
perfcftly open below, after the raodel of Jt
MncqiitT's nicking furnace, and Hands upon it
tripod. The grate is made of flat barbie

on t'.lgc. and witU confiderable interftices. 1:

OF CHtlMtStRY. 549

ate called cuppels. The lead is oxydated^ be-
comes vitrified, and finks into the fiibftance of
the cuppel, while the gold or filvef, being in-
capable of oxydation, remain pure. As lead
will not oxydate without free accefe of air, this
operation cannot be performed in a crucible
placed in the middle of the burning coals of a
furnace, becaule the interrial air, being moftly
already reduced by the combultion into azotic
and carbonic acid gas, is no longer fit for the
oxydation of metals. It was therefore neceflary
to contrive a particular apparatus, in which the
metal fliould be at the fame time expofed to the
influence of violent heat, and defended from con-
taft \^ith air rendered incombuftible by its paf-
fage through burning coals.

The furnace intended for anfwering this double
purpofe is called the cuppelling or eflay furnace.
It is ufu'ally made of a fquare form, as reprefent-
ed PI. XIII. Fig. 8. and lo. having an alh-hole
AABB, a fire-place BBCC, a laboratory CCDD,
and a dome DDEE. The muffle or fmall oven
of baked earth GH, Fig. 9. being placed in the
laboratory of the furnace upon crofs bars of iron,
is adjufted to the opening GG, and luted with
clay foftened in water. The cuppels are placed
in this oven or muffle, and cfc'dtcdil is convey-
ed into the furnace through the *ipeni'ngs of the
dome 'and fire-place. The external air enteits
through the openings of the afh-hole for fup-

M m 3 porting

ELEMENT

yir*-^ the LUMhafti in, sod cfcapcs by the lu-
pmor «pcaiag or ddamev u EE ; and air is
htkcdoac cf Uk muffle GG fbi

Tdj- Safe rdecboa b fofidrat to di£:otcr
tk IIII1IIWI ftipcipfas ^na which this far-
watjt is conftivted. Whca the opening GG is
Aat^^c «ajilMiaa is pcodnced flowly, and with
Afindqr. Sat waM of lir to cairv it on ; and,
wbcB dn bote is open, tb« fltcam of cold air
which B them admicRd fixes the metal, aod ob-
ftmds the pnicc&. The& incocncnieDces may
te aSlj lancdkd, hj coofinidmg the muf&e
and fttmacc m fnch a manner that a ftream of
irdh extenal air Ibould alvays play apon the
fiiHace of the metal, aod this air fhoxild be
made to pais through a pipe of clay kept con-
tinttallj ted hot by ihc fire of the furnace. Bj
thb nicam the iofide of the muffle will never be
cooled, and proccfles will he fini(hed ia a few
minutes which at prelent require a conSdenblc
fpacc of [ime.

Mr Sage remedies thetc tQconvcDteoccs in a
different manner ; he places the cuppel contaia.
tag lead, alloyed with gold or lilver, amoilgfl
the charcoal of an ordioary furnace, and cover-
ed by a fmall porcelain muffle ; when the whole
is fullicienily J^cated, he direds the blaft of i
common pair of hand-bellovrs upon tl;

OF CHEMISTRY. 551

of the metal, and completes the cuppellatioN in
this way with great eafe and esaftneis.

SECT. III.

Of increafing theACliott of Fire, by ufittg Ogygen
Gas inftead of Atmojpberk Air.

By means of large burning-glalTes, fuch as
thofe of Tchirnhaufen and of Mr de Trudaine,
a degree of heat is obtained fomewhat greater
than has hitherto been produced in chemical
furnaces, or even in the ovens of furnaces ufed
for baking hard porcelain. But thefe inftru-
ments are extremely expenfiire, and do not even
produce heat fufEcient to melt crude platina ;
fo that their advantages are by no means fuffi-
cient to compenfate for the difficulty of pro-
curing, and even of ufing them. Concave mir-
rors produce fomewhac more efieA than burn-
ing-glaflcs of the fame diameter, as is proved by
the experiments of Meflrs Macquer and Beaunit-
with the rpcculum of the Abbe Bouriot j but,
as the direiflion of the reflected rays is nccefla-
rily from below upwards, the fubAance to be
operated upon mail be placed in the air with-
out any fupport, which renders moft chemical
experiments impoflible to be performed with this
inftrument.

JM 014

iy-

elements

For thefe reafons, I firft endeavoured I
ploy oxygen ga» in combuftion, by filling large
bladders wilh it, and making it pafs through a
tube capable of being fliut by a llop-cock ; and
in this way I lucceeded in cauBng it to fupport
the combuftion of lighted charcoal. The m-
tenfity of the heat produced, even in my firft
attempt, was fo great as readily to melt a fmall
quantity of crude platina. To the fuccefs of
this attempt is owing the idea of the gazome-
ler, dtfcribed p. 386. et feq. which I fubrtituted
iiillead of the bladders ■, and, as we can give
the oxygen gas any neceflary degree of prefiure,
we can with this inrtniraent keep up a conti-
nued ftrcam, and give it even a very conGdet-
able force.

The only apparatus neceflary for experiments
of this kind confirts of a ftnall table, ABCD,
PI. XII. Fig. 15. with a hole F, through which
pafles a tube of copper or filver, ending in a
very fmall opening at G, and capable ef being
opened or fliut by the llop-cock H, This tube
is continued below the table at /n n 0, and is
connefted with the interior cavity of the gazo-
meter. When we mean to operate, a hole of a few
lines deep muft be made with a chifel in a piece
of charcoal, into which the fubftantc to be treat-
ed is laid ; the charcoal is fet on fire by mean>
of a candle and blow-pipe, after which it is ex-
pofed

OF CHEMiSTRT. 55J

poled to a rapid ilream of oxygen gas from the
extremity G of the tube FG.

This manner of operating can only be ufed
with fuch bodies as may be placed^ without in-^
convenience, in contad with charcoal, fuch as
metals, limple earths, &c. . But for bodies
whofe elements have affinity td charcoal, and
which are confequently decompofed by that
fubftance, fuch as fulphats, phofphats^ and
moil of the neutral falts, metallic glafles, ena-
mels, &.C. we muft ufe a lamp, and make the
ftream of oxygen gas pafs through its flame.
For this purpofe, we ufe the elbowed blow-pipe
ST, inftead of the bent one FG, employed with
charcoal. The heat produced in this fecond
manner is by no means fo intenfe as in the for-
mer way, and is very difficultly made to melt
platina. In this manner of operating with the
lamp, the fubftances are placed in cuppels of cal-
cined bones, or little cups of porcelain, or even
in metallic difhes. If thefe lad are fufficiently
large, they do not melt, becaufe, metals being
good condudlors of heat, the caloric fpreads ra-
pidly through the whole mafs, fo that none of its
parts are very much heated.

In the Memoirs of the Academy for 1782,
p. 476. and for 1783, p. 573, the feries of ex-
periments I have made with this apparatus may
be feen at large. The following are fome of the
principal refults,

I. Rock

fl

i lyrft W pflMMCC ■ BEX glKJUy ^Kltt aMBlfe
Asm M)T k^kxtv KMBVK. Ifecvpper anfiDcatf
Ae fiwacT bbA be ftrrfy aaie of nMEder-
ahle AMcaAoBS, cba the oioacfmAmaA ma^
■M<e DBC MMi^ IBM tibe BD9 BnfltS expSBaMB Ot

APPENDIX-

No, I.

Table for Convertinjt Lines, or Twelfth Parts of
an Inch, and FraSlions of Lines, into Decimal
Fractions of the Inch.

Twelfth Parts

Decimal

Decimal

of a line.

Fra£tiohs«

Lines.

Fraflions.

I

0.00694

I

0.08333

2

0.01389

2

0.16667

3

0.02083

3

o.:f5ooo

4

0.02778

4

0.33333

•

5

0.03472

5

0.41667

6

O.C4167

6

0.50000

7

0.04861

7

0.58333

8

0.05556

8

0.66667

9

0.06250

9

0.75000

lO

0.06944

10

0.83333

II

0.07639

II

0.91667

I?

0.08333

12

1. 00000

No.

^H

■

APPENDIX.

^^H

^^Hl

^

^^^ 558

^W

No. n.

H

^M TABL£/0r

Converting tbe Obferued Heisbti of IVa^

^^ tfr in the

Jars of Che FneumatO'C! emicat Appa-

^B ratas, txprejfed in Inches and Decimatt, to Cor-

^■^^^ re/ponding Heights of Mercury.

^

^^ Water.

Mercury. Water. Mercur/ ^

.1

.00737 4

.294S0

2

.01474 5

.36831

3

.02201 6

.44221

4

.02948 7

•5 '591

5

• .03685 8

.58961

6

.04422 9

.66532

7

.05159 10

.73702

8

.05896 II

.S1072

9

.06633 '^

.88442

I

.07370 13

.96812

4

.14740 14

1.04182

3-

.22010 15

1.1131^^

. ..V. ^

J

APPENDIX.

559

No. HI.
Table for comxrtiitg tbe Ounce Mca/urei ufid
by Br PritJII} into French and Enflijb Cubical
Inches *.

Ounce

French cubi-

Englilh cubi-

V(«riii«.

cal Inches.

csl iiicbcs*

1

'•567

1.898

2

3-134

3-796

3

4.701

5-694

4

6.268

7-59»

i

7-835

9.490

6

9.401

11.388

7

10.969

13.386

8

12.536

l5-'84

9

14-103

17.082

10

15.670

18.980

ao

3«-340

37.960

30

47.010

56.940

40

62.680

75.920

50 .

78-350

94.900

69

94.020

113.880

70

JC9.690

132.860

80

125.360

151.840

90

141.030

170.820

100

. 156.700

189.800

1000

1567.000

1898.000

No.

" The ounce mcafucc of Dr PritttJy contains an ounce

troj, or 480 grains, of puie wuer. The cutiical contents,

H given in the above table, ue K^wdfaiadK Flench

S6o

APPENDIX.

No. IV. Additiohal-
Rtri.ES for Reducing the Degrets of Reatrmfiir*t
and of the Swedi/b Tbermometer, to the Corre-
fponding Degreet on FabrenbeiCj ScaU *.

The fcale of Fahrenheit's thermometer is di-
vided into 212 degrees from Zero, the cold pro-
duced by a freezing mixture of talt and fno'r, to
the temperature of boiling water ; Reaumeur's
fcale has the Zero placed at the temperature of
freezing water or melting ice, and the iotenal
between that and the temperature of boiling
water is iliviiled into 8c degrees : The Sv\edini
thermometer has its Zero in the fame place with
that of Reaumeur, and the interval to the point
of boiling water is divided into too degrees.
Thefe are the principal thermometers now ufed
in Europe, and the temperature indicated by

any

of Mr Lavoificr, reducing tho French meafitrc to Enf^liili
Bocording to llie befl nnd molt generally received compA-
rifon of iheir raiio, m given more at large in No. V. of
this appendix. If, however, the experiments of Mr E'
rtfcl be followed, as noticed in Nc. IX. of the appendix,
the Englilh cubical meafure of one ounce onght lo
been I.8gS9, inllcad of the above. — T.

* In a former edition of this tranllation, a table
given of the degrees on Reaumcur's fcale, with the cone
fponding degrees of Fnhren!ieit, from freezing to bubai
water i but the formulx in this article were tbougl
lenetall^ useful and more convcnicnt.~-T

Lve-
adix, I

APPENDIX,

5^1

I

any of thc« wifty bd reduced into the c<yrrc-
fijondingddgfWiMoti Any bf the^^^^ by means
of the following flmpk .canons ; >m which R fig-
nifies the degrees on the fcale of Reaumeur, F
thore of Fahrenheit, and S thofe of the Swedifti
thermometer.
I. To convert the degrees of Reaumeur to thofe

iDf Fabrenheit ; ■ ■^^■j-jaa:^.

4

1. To contrert di« ^rees of Fahrenheit to
thofe of Reaumeur : ^-^^^^«aR.

3. To convert the Swedifh degrees to thofe of
Fahrenheit ; !^4.32=:F.

4. To Cofivert Fahrenheit's to Swedilh^

9

5. To convert Swedifh degrees to thofe of

Reaumeur ; ^saR.

i

6. To conyert Reaumeur's degrees to Swedifh }

4

To fuch readers as are unacquainted with the
algebraic expreffion of arithmetical formulae, it
will be fufficient to exprefs one or two of thefe
in words to explain their ufe. — i. Multiply the
degree'of Reaumeur by 9, diyide the produd
by 4, and to the quotient add 32, the fum ex-
prefTes the degree on the fcale of Fahrenheit. —
2. From the degree of Fahrenheit fubtraft 32,

N n multiply

5&3

APPENDIX.

multiply the remainder by 4, ^d divide the pfOi«^ •
duft by 9, the quotient is the degree accordiuf
to the fcale of Rcaumeut, &c.

No. V. Additional.

Rules /of Convening French Weights and Meaji
into cerrejpondent Englijb Denominationt •

S I. Weight t.

The Paris pound, poids dc mark of Charle-
magne, contains 9216 Paris grains; it is divided
into 16 ounces, each ounce into 8 gros, and
sach gros into 72 grains. It is equal to 7561
Englifh Troy grains.

The Englilh Troy pound of 12 ounces eon-
tains 5760 Englifti Troy grains, and is equaJ to
7021 Paris grains.

The Englifii avetdupois pound of 16 ounces
contains 7000 Englifli Troy grains, and is equal
to 8538 Paris grains.

To reduce Paris grt. to Englilh Troyl
grj. divide by - - . |

To reduce Englifh Troy jr/. to Paris I
grt. multiply by ... J

To

• For the materials of this Article the Tranflator i* in-
debted to Profeffor Robifon.

Luai

APPENDIX. 563

To reduce Paris ounces to Englifh ^
Troy, divide by - - I

To reduce Englifh Troy ounces to f ^'^^5734
Paris, multiply by - - J

Or the converfion may be made by nieans of
the following Tables,

I. To Reduce French to Engll/b Troy Weight.

Englifh

The Paris pound tz 7561

The ounce = 472.5625 . ^

The gros = 59-0703 f Grains

The grain = .8204J ^^^^^^•

II. To Reduce Engli/b Troy to Paris Weight.

The EngliOi Troy poundl _ i

of 12 ounces, J"" ' I

The Troy ounce, = 585.(13833 } p^^j

The dram of 60 grs. = 73.1354 !

The penny- weight, or de-1 _ ^^ ^ - ^ , l

nier, of 14 g?s. |= ^^.2541 grams,

The fcruple, of 20 grs. = 24,3784
The grain, = 1 . 2 1 89 J

III. To Reduce Engli/b Averdupois to Paris

Weight.

The averdupois pound"] "]

of 16 ounces, or 7000 i>zi8538. I Paris

Troy grains, J r grains.

= 533-6250 J

N n 2 %2.

AFFESniX.

! "-

_ X» nian E^n nkic feet at iocfacs
y-g^j* cobac feet or iacho to htn^

Ocbji

•-°«S9T7'

1.111378

t of the fblinriic nUes:

The Pteis rojal S« ofl _ ^^^^^ T

= .c888 "•=«»•

II inches.

The inch.

The line, or -^ of an inch.

The ^~ of a line.

■rti^w

V. To Reduce EngUJb Long Meafart to Fn

The EngliJh foot, =: 11.2596"!

The inch, - — -Oi^S i

The ^ of an inch, = -"75 VParis inches.

Thcj.^, - -= .C938

The line, or 7^ = .C782J

VL

APPENDIX. 565

\

VI. To. Reduce French Cube Mea/ure to Englijh.

The Paris t ^ En^Jifli f 1

cubcfoot=i.aii278 I cubical I ^093.088384 1 .^^j^

The cubic I fcct, ^ r ^^

inch ?= »oop7ooJ or

2093.088384
X.212278J

VIL To Reduce Engli/b Cube Meqfure to French *.

The Englilh cube foot, 1 _ y gg pFrench

or 1728 cubical inches J ^ ' ^ ^ Vcubical

The cubical inch 2=^ .8260 C- ,

The cube tenth s^ .oopo ^

\ 3. Meafure of Capacity.

The Paris pint contains 58.145 fijCnglifh cu-
bical inches^ and the Englifh wine pint contains

N n 3 28.875

* To convert the weight of a French cubic foot of anjr
particular fubftance given in French grains into the corre*
fponding weight of an Engliib cubic foot in Englifh troj
grains; multiply the French grains by 0.6773181, and
the produd is the number of Englifh troy grains contain-
ed in an EogliQi cubic foot of the fame fubfiance.

f It is faid by Belidor, Arcbii, Hydrog. to contain 31 02?.
^' fr/. of water, which makes it 58.075 Englifh inches ; At

Dofiderable uncertainty iiTthe determina-

tions

568

APPENDIX.

3. To redace the Swediflj pound, ounce, d
fcruple, or grain, to the correfponding Englttk
troy denomination, maitiply bj 1.1382, or divide
by .8786.

4. To reduce the Swedifh Kannes to Elnglifh
wine pints, multiply by .J520207, or divide bj
6.57804.

5. Tbe Lod, a weight fometimes ulcd^
Bergman, ii tbe ^zd part of the Swedifli potx
Therefore to reduce it to the Engliih troy pound,
multiply by .C3557, or divide by 28.1156.

APPENDIX.

569

.i .

No. VII.

Table of the Weights of the different Gaffes^ at
28 Trench inches^ or 29.85 Englijh inches ha^
rometrical preffure^ and at 54.5** of tempera--
ture, expreffed in Ungli/b tneajure and Englt/b
Troy weight.

KaoMS of 1 Specific gravity. Wnglit of t cv-

the Ga&s. ^^ wftter being zooo. bical foot in giv.

Atmofpheric ♦ .1.2308 538.45

Azotic
Oxygen
Hydrogen
Carbonic acid

Nitrous
Ammoniacal
Sulphurous acid 1.8856

1.1890

1.3562
0.094671

1.8454

1463X
0.73539

520.17

593-3^
41.41

807.34

640.09

321.72
824.98

Weight of a ca-
bicaliochingn.

.311023
•^43X54

•343345
•023964

.467326

.370422

•I 861 80
.471631

No.

* Thefe five were afcertained bj Mr Lavoi&r him-
fclf.— T.

* * The laft three are inferted by Mr Lavoifler upoa
the authority of Mr Kirwan*-*-T.

Hi

^^^^^^H

HH^^^^^^^^^^^^^^^^^^^^^I

W"

^./^

m

^p ^73 APPENDIX.

M

V No. VIII.

^

^L^^, Tables of ibe Specific Gravitiet of different BodiJ^^^

^^^^ft- § I. Metallic Suhjlances.
^JU.-, GOLD.

^M

■^M

Pure gold of 24 carats melted but no(

^^1

hammered.

19.2581 1

The fame hammered,

'9-3^'7 . J

Gold of the Parifian ftandard, 22 carats

fine, not hammered *,

17.4863^^1

The fame hammered,

^7-S»94^M

Gold of the ftandard of French coin,

2i||- carats line, not hammered,

17-4°>4^H

The fame coined,

'7-64'^^M

Gold of the French trinket ftandard,

20 carats fine, not hammered.

15-7093^^

The fame hammered,

"5-774<> 1

SILVER.

^J

Pure or virgin filver, 12 deniers, not

^H

hammered.

i°'474^^|

The fame hammered.

i°'5io;^H

Silverof the Paris ftandard, 11 deniers

10 grains fine, not hammered f,

i°'i75:^^|

The fame hammered.

io.376^^H

SilTCt^H

(- • The fame with Sterling.

^^H

^^ t This ia lo^rj. finer [ban Sterling,

'^' ^1

/^^H

APPENDIX.

sn

Silver, ftandard of Freach coia, xo de-

niers 21 grains fine, not hammeredt 10.0476
The fame coined, - - 10.4077

PLATINA.

Crude platioa in grains, - 15.6017
The fame, after being treated with mu-
riatic acid, - - 16.7511
purified platina, not hammered, 19.5000
The &me hammered, - • 20.3366
The fame drawn into wire, - . ai.0417
7^e fame pafled through rollers, 32.0690

COPPER AND BRASS.

7.7880

The fame wire drawn.

8.878s

Brafs not hammered, .

8.3958

The lame wire drawn.

«-544I

Common call brafs, - -

7.8240

IRON AND STEEL.

Caft iron, - -

7.1070

Bar iron, either hardened or not.

7.7880

Steel, neither tempered nor hardened.

7-8331

Steel hardened under the hammer but

' nottempeied, - - 7.8404

Steel tempered and hardened, - 7.8180

Steel, tempered and not hardened, 7.8 1 63

OTHER

i p. P END IX.

S7J

Oriontal Piftachio toptu

4.0615

BnSllian ditto

3-5365

Sbxod ditto

3.5640

Ditto white ditto

3.5535

Oxiental Saphir

3-994«

Ditto white diuo

3-99l«

Saphir of Fujr

4.0769

Ditto of Brafil

3-'307

GinTol

4.0000

Ceylon jargon

4.4l<«

Hyacinth

3-6873

Vennillion

4.M99

Bohemian garnet

4.t888

Dodecahedral ditto

4.0627

Syrian ditto

4.0000

Volcanic ditto with 44 fidea

3.4684

Peruvian emerald

»-7755

Cryfolite ot the jewdlera

a.7811

Ditto of firalil

1.6923

Berylt or Oriental aqua marine

3-5489

Occidental aqua marine

1.7227

S 3. Siliamu SUiui.

Pure rock cryftal of Madagafcar

2.6530

Ditto of Brafil

a.6526

Ditto of Europe, or gelatinous

2-6548

Cryllallized quarts

2.6546

Amorphous ditto

2.6471

Orieutal agate

2.5901

Agate

^■I^I^^B

574 APPENDIX.

n

Agate onyx

_

^•63;^^

Tranfparent calcedony

-

2.6640

Carnelian

-

1.6137

Sardonyx

, -

2.6015

Frafe

2.5805

Onyx pebble

-

2.6644

Pebble of Rennes

-

2-6538

White jade

-

2.9502

Green jade

-

2.9660

Redjafper

-

2.66i3

Brown ditto

-

2.691 1

Yellow ditto

-

2.7IOI

Violet ditto

-

2.7III

Grey ditto

-

2,7640

Jafponyx

-

2.8160

£lack prifmatic hexahedral fchorl

3-385^

Black fpary ditto

-

3-3851

Black amphorous fcharl.

bafaltes

-

^9^^H

Paving ftone

-

a-t4^H

Grind (lone

_

X14^^

Cutler's ftone

_

2.1113

Fountainbleau ftone

.

2.5616

Scyth ilone of Auvergne

.

2.5638

Ditto of Lorrain

_

2.5298

Mill ftone

-

^•4835 :

"White flint

.

2.5941 1

Blackifli ditto

nu

APPENDIX. 575

§ 4. Various Siones, ISc.

Ojpake green Italian ferpentine, or gabro

of the Florentines - - ^•4^95

Goarfe Brian^on chalk - ^'7^74

Spanifh chalk - - 2.790Z

Foliated lapis oUaris of Dauphiny 2.7687

Ditto ditto from Sweden - 2.S531

Mufcovy talc - - ^-79^7

Black mica - - 2*9004

Common fchiftus or flate • 2.671s

Newflate - - ^-^535

White rafor hone - 2-8763

Bl ack and white hone - 3* 1 3 ^ i

Rhombic or Iceland cryftal • ^*7^S^

Fyranndal calcareous fpar - 2*7302

Oriental or white antique alabafter 2.7x41

Green Campan marble • 2.7417

Red Campan marble - 2.7^42

White Carara marble - 2.7168

White Parian marble - 2.8376

Various kinks of Calcareous ftones"! from 1.3864

ufed in France for building J to 2.3902

Ore of Uranium - - 7-5ooo

Heavy fpar - - 4*4300

Strontitic fpar . " X3-7^6o

White fluor - - 3-IS5S

Red ditto - * '^.igii

Green ditto - - 3«i8i7

~iie ditto - . 3.1688

Violet

L^Hi^^H

576 APPENDIX.

Violrt fioor

3-1757

Red tciaulaot zeottte from Edelibrs

i-4868

White fcintildnt zeclite

3.0739

CiyftjlUicd zeolite

2.0833

Biack pitch ftoQC

1-P499

Yellow pitch ftoae

I.oS6b

Red ditto

a.«6M

BtacUih ditto

2.319*

Red poeph viy

2.7«5«

Ditto of Dauphinj

a.703J

* Green fcrpentine

x89«a

Black ditto of Dauphinv, called variollte a.933j} |

Gccca ditto from Dauphiny

1.9883

Ophites

1.9721

Cnnitcllo

3.c6a6

Red ZgrptiaD graniu

3-6541

Beautiiiil red granite

1.7609

Gianile of Giiardmas

1.7163

Pnmice ftone

.9H5

Lapis obfidianus

2.34*>

Pierre de Volvic

1JK>5

Touch ftoae

M^SJ

Bafaltes from Giants Caufewajr

2.8641

Ditto pnfmatic from Au\-erpie

3-4'53

Glafs gall

2.8548

Bottle glafs

2.7315

Green glafs

2.6423

White glafs

2.$Sa^J

St Gobin ctjflal

3.^H

Leith cr}-fial

1

APPENDIX.

577

Flint glafs -

3-3»9J

Borax glafs - r

2.6070

Scves porcelain

2-1457

Limoges ditto

2.3410

China ditto

2.3847

Native fulphur

2.033a

Melted fulphur

1.9907

Phofphorus

1.7140

Hard peat

.1.3 i90

Ambergreafe

■ .^263

Yellow tranfparent amber

J .07 80

§ 5* Liquids.

Diftilled water

I.OOOO

Rain water

1. 0000

Filtered water of the Seine

1. 0061 5,

Arcueil water

1.00046

Avray water

1.00043

Sea water

1.0263

Water of the Dead Sea

1.1403

Burgundy wine

.9915

Bourdeaux ditto

•9939

ft

Malmfej Madeira

1.0382

Red beer

1.0338

White ditto

1.0231

Cyder - - -

1.0181

Highly redified alkohol

.8293

Common fpirits of wine

.837X

Oo

Alkohol

H

■1

APPENDIX.

1

^^^^ Alkohol

1 5 pl5. water l part-

:dP

14 -

'3 3

.Mis

12 4

J947

Ji 5

•9<=r5

10 6

-9>99

9 7-

•93 '7

8 8 -

*t»7

7 9

•95'9

6 10

•9594

5 "

•9*74

4 12

■9733

3 "3

•979'

2 14

.9851

^^^^^ft c

• >5

.9915,

^^^V fiulphuric ether

.7394

^^^^B Nitric ctlier

.9^8!

^^^^B Muriatj

c ether

•7298

^^^^V Acetic

ether

.8664

^^m highly

concentrated Sulphuric acid

2.1250

^^^^H Common Sulphuric acid

J.8409

^^H Highly

concentrated Nitric acid

1.58M

^^^■^ Comjiwn Nitric ditto

'•»7?9

^r Muriatic ditto

1.1940

^K Fluoric

acid

I.50OT

^V Red acetous ditto

1.025X

^M White acetous ditto

i^oijs

H pjSiiled ditto ditto

1.0093

Acetic

APP-ENDIX.

579

Acetic ditto

_

■ j.o6i6

Formic ditto

.9942'

Solution of cauftic ammoniac, or vola-

tile alkali fiuor

.8970

£fli:ntial or volatile oil of

turpentine

.8697

Liquid turpentine

-

.9910

Volatile oil of lavender

.8938

Volatile oil of cloves

..-• ,

1.0363

Volatile oil of cinnamon

.

1.0439

Oil of olives

-

-9153

Oil of fweet almonds

■ - '

;. .9170

Lintfeed oil

...

•I9403

Oilof poppy feed

-

■ .9288

Oil of beech .maft

.

.917S

Whale oil

-

•9233

Womans milk

.

1.0203

Mares milk

-

1.034S

Ms m'dk

-

1-0355

Goats milk

.

1.0341

Ewe milk

-

1.0409

Cows milk.

-

1.0324

Cow. whey

J.0193

Human urine

-

1.010$

§ 6. Refins and Gums.

Common yellow or white rofin 1.0727

ArcanJba. - - 1-0857

O o 2 ... Galipot

■

^

g83 APPENDIX.

^

Galipot *

i.olfl^

Batas*

■

1.0441 1

Sandarac

-

l.opao

Mallic

-

i.o74i

Storax

1.1098

Opake copal

-

11398

Tranffiarent ditto

-

1.045J

Madagafcar ditto

i.c6oo

ehinefe ditto

-

1.063S

Elemi

-

1.018a

Oriental aniine

.

1.CZ84

Occidental diuo

.

1.0426

Lftbdanum

.

1.1862

Ditto in torth

.

^•493J

Refm of guaiac

-

1.2289

Ditto of jallap

-

1.2185

Dragons blood

-

I-J045

Gil in lac

-

1.1390

Tacaraahaca

-

1.0463

Benzoin

-

1.0924

Alnucliif

-

1.0604

Caragna %

-

1.1244

Elaftic gum

.

•9335

Camphor

-

.98S7

Gum ammoniac

1.2071

Sagapenura

-

1.2008
1-7

* RcGnnus juices r^tra^ed !a France from the Fine. \

^^ Vidt Bamati, ma.

^^^^b ' f Oilorifcrous gum

from the tree wliich

produces At

^^^^^ CeriM Wimeranus.

lUJ.

^^^^^K Relln the tree

called in Mexieo, Caragna, or Tiw J

^^

APPENDIX. 5»i

Ivygtim*

-

1.2948

Gamboge

-

1.22 1 6

Euphorbiuni

flV flS

1. 1244

Olibanum

•

1.1732

Myrrh

. .

X.3600

.Bdeilium

^

«• «•

1-371^

Aleppo Scamony

- .

1.2354

Smyrna ditto

-

1.2743

Galbanum

-

I.2Z20

Aflafictida

•

i.3275

Sarcocolla

- -

1:2684

Opoponax

-

1^6226

Cheny-tree gum

-

i-48i7

Gum Arabic

-

1-4523

Tragacanth

-

1.3x^1

Bafora gum

-

1.4346

Acajou gum f

-

1.4456

Monbain gum X

«■ m

1.4296

Infpidated juice of liqiiorlce

i.7228

— Acacia

^.•5i53

■ — ^

— k Areca

1-4573

Terri Japonica

•

1.3980

Hepatic aloes

•» «•

i-3586

Socotrine aloes

^ «•

1-3795

InfpifTated juice <

af St John's wort

.i'5263

Oaa

Opium

* Extraded in Perfia and the Wa^rm countries from He-
dera ttrte&ns.'^Bomare.

f From a Brafilian tree of this namc^—l^at

t From a tree of this mmt^-^Ibid,

r 58J

APPENDIX.

g

1 Opium

1 InUigo

-

*J3«

.7690

f Arnotto

1 Yeliow wax

L White ditto

^^^^^jOuarouchi ditto * - -

■5956
.9648
.9686

^^^^Epacao butter

-

■M^l

^^■^ pperraaceti

.

'9^^l

[ Beef fat

_

■9^^|

U Veal fat

.

■9^^l

^^^^^^utton fat
^^Hfallow
^^^ Hoggs fat
f Lard
1 Butter

-

•9»3S
.9419
.9368
.9478
■94>^^

Hflp^.r'

} ^. ivosd,.

1

Hedrt of oak 6o years old

1.1700

Cork '
Elm trunk
Afli "ditto
Beeih'
Alder

.34C0

^..lA - — "

.6710

.8450

Maple
Walnut

-■■(VnrloT !?■?"; ^, :

■79
.6710^

Willow

-

•5830

Linden

-

.6040
Mile

^k • Tlie produce

^^ Bomart'i dm. 1

iJ

APPENDIX. ^

Male fir - - .55:^

Female dittO| ■ ,. - ■ - . .4980

Poplar - - .3830

White Spaoifh ditto - • -5294

Apple tfce - -^ . - , .7930

Pear tree .-,.,■ ,-' , . .6610
Quincetree - .>*;,■.■-,....,,-.., .-7050

Medlar - - -9440
Plumb tree .,-:....-;-. '7850

Onve'.wood ! - ' r .. ' , -9^79

Cherry tree - .-. , -7150

Filticrt tree . ' - -' , ■ -^^9?

French box - r . , ... •9'^.'9

DqtcTi ilitto - - ", .' 1.32B3

Dutch yew ' ' - - ' . ■7^.p9

Spanifti ditto , - - / .8070

Spanifh cjpr'efs. " - * -',' , .6443

American cedar - - .5608

Porhegranate tree - - 1-3540

Spanifii mulberry tree - - _ .8970

Lignum vitie . - , - . ^■333^

Orange tree - ' -. , -7050

O o 4 No.

A^off.— The numbers tn the above Table, if the Decimal
point be carried thit^e figures farther to the right hunt),
nearly expi -f^ the nbfolute weight o£ an Englifli cube foot
each fubftance in averdupoit ounces. Sec No. IX. of
the Appendix.— T.

SH

APPENDIX.

No. IX. Additiokal. -'m

Rules for Cakuhttng the AhfohU Grat^y ht
Etglsjh Troy tVeigbl of a Cubic Foot and Inch,
Engiijh Meafare, of any Subflance ivboje S^-

cific Gravity is known*.

In l6q6. Mr Everard, balance- maker to the
Exchequer, weighed before the CommilGoners
of the Houfe of Commons 2145.6 cabical inches,
"by the Exchequer ftandard foot, of diftilled
water, at the temperature of 55° of Fahren-
heit, and found it to weigh II31 oz. 14 drs,
Troy, of the Exchequer ftandard. The beam
turned with 6 grs. when loaded with 30 pounds
in each fcale. Hence, luppofing the pound
averdupcis to weigh 70C0 grs. Troy, a cubic
foot of ivater weighs 62I pounds averdupoii
or 1000 ounces averdupois, wanting 106 grains
Troy. And hence, if the fpccific gravity of
»vater be called 1000, the proportional IpcciBc
gravities of all other bodies will nearly exprefs
the number of averdupois ounces in a cubic
foot. Or more accurately, fuppofing the fpeci-
fic gravity of water exprefled by i. and of all
other bodies in proportional numbers, as the
cubic

• The whole of I^i= and the following article
muDicnted to the Tiaollator by ProfcQbr Robifon. — 1m

. ARP E N DJ X. 585

cubic foot of water weighs, at the above tern*
petature^ exadly 437489.4 grains Troy^ and
the cubic inch of. .water ^53^17$ grains^ the
abfolute weight of a cubical £x>t or inch of
any body: in Troy grains^ may be found by mul-
tiplying their fpecific gravity by either of the
above numbers refpe&ively.

By Everard's experiment, and the proportions
of the Englilh and French Foot, as eftabltfhed
by the Royal Society and French Academy of
Sciences, the following numbers are afcertain-
ed.

Paris grains in a Paris cube foot of

water - - =645511

£ngli(h grains in a Paris cube foot

of water - - =529922

Paris grains in an EngliQi cube foot

of water - - =533247

Englifh grains in an Englifh cube

foot of water - - = 437489.4

Englifh grains in an Englifh cube

inch of water - - =253.175

By an experiment of Picard with
the meafure and weight of the
Chatelet, the Paris cube foot of
water contains of Paris grains = 641326

By one of Du Hamel, made with

great care - - =641376

By Homberg - - = 641666

Thefc

5S6

APPENDIX.

Thefe (hew fome oncertainty in meafure or
in weights : but the above computation from

■Bverard's experiment may be relied on, bc-
caul'e the comparifon of the foot of England
■with that of France was made by the joint la-
bour of the Royal Society of London and the
French Academy of Sciences: It agrees like-
wife very nearly with the weight afligned by Mr

' LaToitier, Tofnris pounds to the cubical foot^
water.

^PPENmi-X.

"^

Tables for Converting Qunfes, Drams ^ and
Grains^ Troy^ into Decimals of the Troy Pound
of 12 Ounces J and for Converting Decimals of
the Pound Troy into Ounces^ &c»

I. For Grains.

Grains es Pound.

Grains

^ Pound.

I

.0001736'

100

.0173611

2

.0003472

200

.0374222

3

.0005208

300

.0520833

4

.0006944

40^" ■

0.694444

5

.0008681

500

.0868055

6

.0010417

1 ■■

600"^

•1041666

7

.0011153';

700

.1215277

8

.001^889

!J00

.1388888

9

•0015615

900

.1562499

lO

.COI736I

1000 "

.1736110

20

•0034712

2000

.3472220

30

.0052083 '

3000

•5208330

40

•0069444

4000

•6944440

50

•0086806

5000

.8680550

60

•0104167

6000

1.04 1 8660

70

.0121528

7000

1.2152770

go

•CI38889 "

80CO

1.3888880

(JO

•OI5625O

9OCO

1.5624990

II.

ft 588

g

^^H

z

^^^^^^^^H

APPENDIX.

K-

II.

For Drams. i

^M

^^■'

Drams s

= Pound.

^M

^K.

1

.0104167

'fl

.020S333

^^^H"

3

.0312500

^^1

^^^K

4

.0416667

^H

^^^K

5

.0520833

^^1

^^^K

6

.0625000

^^1

^^^r

7

.0729167

^H

^^L_^

8

•0833333

^^H

^^V"

III.

For Ounces.

^H

^^^^^'

Ounces

= Pound.

^^^B

^^^v

1

•0833333

^H

^^^■'

2

.1666667

^H

^^H

3

,2500000

^^1

^^^H

4

■3333333

^^H

^^^B'

5

.4166667

^^1

^^^H

6

.5000000

^^H

^^^H

7

•S«33333

^^H

^^^1

8

.66!*6667

^^^1

^^^H

9

.750000a

^^^H

^^^V

lo

■8333333

^^H

^^^p

11

.9166667

^^^

r

la

1.0000000

'^^1

l^_

^^_

^1

APPENDIX.

5«^

IV. Decimals qf the Pound ititt Ounces, \^c.

Tenth parts.

Thoufandtbs.

lib. =

05S. a#*. gT*

lib.^

grs.

O.I

I I 36

0.006

34-56

0.2

2 3 12

0.007

40.32

0.3

3 4 48

0.008

46.08

0.4

4 6 24

0.009

51.84

0.5

600

Ten thQu/andth parts.

o.(5

7 I 36

o.oooz

0.576

0.7

8 3 12

0.0002

1. 152

0.8

9 4 48

0.0003

1.728

0.9

10 6 2^

0.0004

2.304

Hundredth parts.

0.0005

2.880

o.gi

0 0 57,6

0.0006

3-456

0.02

0 I 55.2

0.0007

4.032

0.03

p 2 52.8

0.0008

4.608

0.04

0 3 50-4

0.0009

5.184

0.05

0 4 48.0 ^

Hundred thoufandth

0.06

0 5 45-6

parts^

0.07

0 6 43.2

o.ooooi

0.057

0.08

0 7 40.8

0.0Q002

oais

0.09 .

0 8 38.4

0.00003

0.173

4

•

Thoufandtbs.

0.00004

0.230

0.00 1

0 0 5.76

0.00005

0.288

0.002

0 0 11.52

0.00006

0,346

C.C03

0 0 17.28

Q.OOOO7

0.403

p. 004

0 0 23.04

o.ocooJl

0.461

0.005

0 0 28.80

0.00009

0.518

No.

^^^ «»

^^H

APPENDIX. ^^1

No

^^H

^H Table of the Engli/b Cubical Inchei and Decimals

^H corresponding tft a determinate Troy weight of

H diflilled Water of the

Temperature of 55", cal-

^B culatedfrom Everard

1 Experiment

/or Graint

For Ouncei.

^1

Ciibicat Inches.

Oz. Cubical laches.

^1

= .0039

I x= 1.8959

^m

•0079

2 3.7918

H

.0118

3 5^6877

B

.0158

4 7-5837

^H

•0197

s 9-4796

^■'

.0237

"i 'I-375S

H

.0270

7 '3^27i4

H

.0316

8 i5^i<i74

H

•0355

9 I7'0'i33

^K

•°395

10 18.9592

^H

.0790

II 20.8551

H

.11S5

^B

.1580

Tor Founds.

^B

■■974

Libs. Cubical Inches.
' = 22.7510

^or Drams.

2 45-502I

^^ Dism

. Cubical Inches.

3 68.2531

^B

= -2370

4 91.0041

^H ^

•4739

5 113-7553 •

B

.7109

6 136.5063

■

•9479
1.1% _ _

7 159-^574

8 182.0084

1.4119 -

9 204.7595

1.6J89

10 227.5106

50 11375530

100 2275.1061

10^2 22751.061J

^^^^K

No.

APPENDIX, 59*

Now XII. Adsitiomal.

Table <f the Comparative Htati of diffiriMt Sadies^ as
ajcertained by Crawford,

Hydrogen p.t - . 4(.4Qo*

Oxygen gal . . 4-749^

Aunofpheric ur - . ■ 1.7900

StcuD 01 aqueoul npou; ' • , ' - 1.5500

Ciibonk acid g» - • . 1.0454

Arteiul blood - 1.0J00

W.ter - - i-oooo

Cows milk - - -9995

VcnoQi blood . . .S91B

Aioliogu - - .793*

Bide of >o <n wiili ihe hair - - .7I70

Lungs ofa Iheep - - .JS90

MufcuUr flelb of an ox . - .7400

Alkobol - - .ec-ii

Rice . - .sofio

Hoifc beam ■ • ,5010

Spermaceti oil ■ . •jooo

Fruit of tbe pine tree - ■ ,500a

Pea ft . -49*0
Wheat
Batlejr

Oat> - • .4i.fia

Sulphuric acid . -4190

Pilcoil . - -ij?'

Charcoal • - -i^ji

Cbaik • . .^^6^

Ruft of iron - - .1500

Walhfd diaphoretic Antimopy - - . .1171

Onyd of copper nearly freed from air , .1171

t^icklime . . .1119

Cinders . '. ' , .1913

AQici of Pitcoal - . .1855

Ruft of iron oearlj freed from air . . ,1666

Waflicd diaphoretic Antimony Do. - J1666

Albf i of elm wood . - .1401

Oijd of Zinc nrailj- freed frijpi »ir - .13*9

■4770

APPEKDIX.

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