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About Google Book Search Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web at|http: //books .google .com/I *^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 •^ 4 Sv * \ V VN >^ * UBR4Pr Of THE — •» •0 /;-'/i/r/?.9/./, asA-fcl'^ .)').. 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