Experiments and Observations Relating to the Principle of Acidity, the Composition ofWater, and Phlogiston. By Joseph Priestley, LL. D. F. R. S.Author(s): Joseph PriestleyReviewed work(s):Source: Philosophical Transactions of the Royal Society of London, Vol. 78 (1788), pp. 147-157Published by:Stable URL: http://www.jstor.org/stable/106653 .Accessed: 04/11/2011 14:09

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact support@jstor.org.

http://www.jstor.org

XXI. Expergmexts and OliAgrvazX*ons reivtgbag to zEse Prt*zcis C

Reail February 7s, X ^88

tI4AT ozater con{iRs of two kitlds of air dephiogilli- X cated and irflammableg is IIOW, I beAieveg generally

adLmitted as one of the moR tmportatlts and beI} aCcertained} doAaitzes ill chemifiry. WI\T own experiments havit:lg feemed to fivour it, I tnade lwo difficulty of rectiving zit myfelf: but- havingS at the time of the publication of the laR Volutner of my Experimerltsa froutld that in decompofing the two kitlds of atr alsove mentioned by the eleEtric fpark I got much- leIi vater thatl I exped:edX andX inRead of it, a dark-coloured va pour, not earlly condenfedS I could not help collcluding that fomethitl=g yet rerllaitled to be inveIligated with refpeEt to this fubjed7 atld dererminedX a-t a proper opportunity, to refiume

* . * * * : -

tny llzqulrles lnto 1t

At that timeb however I had no fufpiciotl of any acid I)eirlg prodtlcecl ill the pL-oce; ilaviTlg; Ilel7er been able to fiLad arly in the wtater which t had hitlzerto procured itl pretty large quarutities from the deconpcxfit:io) of tglaoSe tsvo klds of airs thotlgl:l the dodrilae of c7ephloglfl:icated air lCtng czr CO!;ltAill igS the pliIlciple of snices,EJaI ar&1'd@7g t12d. bee astallced - M. L}AVQISIERX arld adrnitted by INyfelf a

14-3 DRl. PRIESTLEYgS Experlgents and Ofer

AZcidys the Compofziox of MaZerX and Pherave 49 The lnercury l)eing aI] ilNpediment ill this proceC 1 afterward:s

COllfiIlCd ttle miXtUreOfair ill Ol:le Veflel (\Vith mercury and fixed aulmoniac as befc)re) but I made the explo{iotls in aIlothers which lihacl previoutly exllauIled of air. tRhis ve{Nel was larger tha tleat vvllich I had uSed before contaitlilog fomething nwore than eigllt oualce meafures, I:o that the air it containedf lDeirlg one- third dephlot,iRicated atld two-thirds inflammalJleS wwould have weIghed about two graihs. After ollie ex'plefiorl the quantity of water colleded appearitlg it nal air, I could pour it from one end of tthe veSei to the other; alld it feemied to fall almoftSas fifl: as a feathel ill a common vacuum, and irl general i did not diSappear in lefs that} > ten minutes. I even found this denfe vwour;svhen the mixture of air had f beetl confirled- by water The fmell of -the reSels after the proceSs, Awas that: of the moI} offellflve kind of iilu flammable air from iron

From thefe experiments it was- fuifiiciently- evident, that fomething more -thatl cwater had been -produced, alld pouri into the veSel a QUIltity Qf tShev juice of littnus, it was itlv Rantly turned to a dcep red > fo that it: was cqually evidentf

that

X 5O D}^. PRI ESF1 LE Y S EX2ertA7FGnZ3 AX1 ObZV4ZtO8S OSX hat an atiX lasd beeal fbrtned. It1 all the preceding experiZ metlts the depillog;iRicated air 11ad been procured from man- gancS, atlfi ill t1t tlle experiments mentiotled in this Paper, tlle iilflammable air was from: irotl ly water only

A great 1luruber of Ilrong glafs vefiels havitlg beetl broke itl thefe experitnents, alld folnetimes with fome hazard to my- felf; aIld tlle quatltity of air that I was able to deco-mpofe in them being flnal], I next procured a C@per veISel, which colltained about tllirty-fix outlce meafures of ais; and havitlg now no otEler objed; thatl diScoveril}g the kind of acid that I had pro- cured} 1 made repeated experitnents in it; and after every tetl or twelve explotions colleEted all the liquid matter I could fintl; vlaicl1 as the air had been previoully cot1fined by water, Fas pretty confiderable, about equal to the weight of the air.

The liquor that I procured in this maurwer was alsrays of a qdeep blue or greetl beia1g evidently a COINtiOI1 of copper. But it aIIb col1tained a redurldarlt acqid, as appeared by its turnitlg the Juice of litmus red. Bef1des this blueW liquor, there was always a qualljtity of Seemingly abraded copper; for it was 1erfied1y and quicllsly diIBlved by volatile alkali as copper very minutely divided would have bee

LAcidi5t e Co8poftiox tf [Iater, and PhA3ffloa. l 5-I By the ailRance 0f l\/lr. KEIR I extamined thefe folutions C}5

copper and prefently foutldX by mealas of a itolution of terra potaderofa ill fpirit of faltn that it svas IlOtv in any of # the caCes,

-the s?itriolic; atad ,>tetX uS the dry fubllatlce left by tht! evapo- ration of the liquor did IlOt deliquefce I had ccncluded, that the acid was neither tlle IlitrousX 1lor the marine; but 1Mh REIR informs me, tlwat this is the cafe with-a fully faturated folution c)f copper is fptrit of rwitre, > >

AIfo Dr. NVITMERINGX xvho was fo oluligitlg-as to examine forlze of theSe liquors fior me (forX not SCiL1g tnuch accu{tomed to theSe analySesS I had requei:led hltu to ulldertak>*e it) had pro cured frotn that in the produEiotl of which the red lead 1and been uSed9 cryflals of nitre, :and otller- indifputable itldicatiots of nitrous acid; fo that I was fatisEed that it !\as ttliS ActCI tI:-lat xYas produced itl all the caSes.

I had a :farther proof of the acid being the llitrC)U5:s tt1Ult llaviIlg (in order to get a quantity of liquor that fhould be as little faturated svith anyq rnetal as poElble) uSed a veflel of svnneff ronS I found, that after forne time, when the tin had l;ee rrallch corroded -(atld writh every proceEs a conElderable quan tity calue away3 the liquors which at firR was colourlefs7 was tinged with redO In thefe experiments T mas:le ufe of dephlo giRicated air from red lead.

As both the kinds of air made uSe of in thefe experimetts were exceedingly pute it Seetns evidentS tElat phloglRicated air docs not contain all the eleLneIlts of laitrous acid; but otlly Iipplies a he for it, tlle deplllogifl:icatnd air (wllicll 6ras uSed in a greater proportiozl in the vatuable experiment of }Wl'o C8A VENDISH) FUPPIYi[1g t11C atidifyillg principle as I had cons jeEtured iil the 1aR Yolutne of my Experiments, p. 40+* Be- fides3 tbougll all plllogifl:icated air CoUld nOt 1Je eXC1VldEd iS1 thQWe

Z exper

l 5 lDr. PRTESTLFXY9S EzpertmenZs axd Ob/ers4zions on expelFimewts in which the air-ptlmp svas uSed tlais objeAioll CAtillOt well be made to thoSe itl svhich that itlS-rume1Rt was

or ufed; atld it} tllern the fosvly condellfable vapour above rnetltioned Seems to le an evidellt fymptom that tlAe producq vas llot mere srater. But it is a fatisfaAory atlfwer to this objeAion, fro>n the preitlce of phloC;/?iced agr irl the tube, tiaat this llSitad of air is nor decompofed, or at all affeded, by t}ts procefsg as wlll be foutld by txlixing any quantity of it nritll tlle tzvo other kindts of a;r.

tRhat a confiderable qualltity of water enters illtO the com- POfit;OL1 of dephlogifiicated air, will not be thought impro 13able? svhen it is confldered that7 in my fortner experimerlts, tllis appeared to be tlle caSe with reEpeA to ifamfnable air. For witilout ^ rater this air calnot le procured. I can alSo now fay, that the fame is the cafe with refpeEt to fiwed air. It- is not tllerefore improbabl-e, that the fame may-be true of every other killd of air, fince water is nfed itl the produScioll of them all.

Terra ponderoSa aerata (a fubRarlce of which Dr.WITH:E:RING - has given us all excellent at;alyEs) gives no fixed air by mere-heat But I fitud, that whell lleam is Sent over it, in a red heats in an earthen tube, fixed air is produced with the greateR rapi- dityX and in the fame quantity as when it is diffolved in rpirit 05 ralt: and, makil}E; the experiment with the greatefi care, I find, that fixed air cnilfiRs of alDout half its weight of water.

From two ounces of the terra ponderofa I got, by meatls of Ileam, I90 ounce meafures of fixed aiir, fo pure that at firR X 50 orlnce meafures of it vere reduced by agitation itl water to 3z, atld-of the laR produce, 30 ounce meaElilres were reduced to one. :xamilling the refduum of the firR portion by rneans of aitrous air I foulad it to be of the Ilandard of 1.5.

After

y Ae Xzltisa of 1nvr, axd Pon. x:S3 After this} ttteNC lilg to the x}vzer txpetlded il} the p-rowli, I

iund that I procured 3o ouwce meafilres o Xe.d air w;t-}} tne lofi of 6s graxXls of sYZatPr A-ccorditlg to t:}wiss as the air weighed z94 gransX Y the svater m the Sxed air muft have 62tIl 8s parts vf X47 of tlle sv}wole

tu aotller esperirmellt} lavng- prevloutly fbutldf that thr outlces of the terra ponderofa ylel-ded about 2so ounce mslires of fixedk airfl I attended ouly to the lofi of water in pmcurilzg itf and I S;3und it to be about one*fiRh nf atl ounces in t;wo fuc neflisre trialsO The quatltity of fixed air would weigh zzS glainsy and the water expeaded about xoo graitas, b that} ;a this experitnent alIbs tlae fixed air muR l

I54 13r. PRIESTLEY9S EwSeri>S8ls and ObJarvvZs on o;f the fixed air carries oF part of the water in the men- ftuurn; and that this part of the welght is about one-half of athe svhole

I tmuA obferveX tha:t the ]ppO6tiOIl Of svaterR enteiring itlto -the conIlitutiota of all the kiIlds of airX ancl beitlg, as it vere, thei-r proper baj4Sw tlant xvithout which- no aeriirm fubflcance can fubfilR (wllich the prececling experiments render in- a high - degree probable) makes it tl-uneCeary to fupporeg-. aS myfelf as well as others laave done that s^7ater confiRs of dephlogilRi cated air and tuflatnmab-le air, or thatb it- has ever been either cornpofed or decompoIid itl any of our proceXes.

That s^7ater is decompoSed when inflatnmalJle alr is procured from iroI:w by Ileam i-s not probalJle ; firlce the illflammable jprin- ciple may very svell l)e fuppoSed to come from t-he irong- and the additioil of veigilt acquiled bo the iron rriay be afcrilJed to tlle tvvzer twhich has dif^placed it. Alfo when the Jcale of iron, orfinery cinder, is heated in inflammable air, it gives out what: vit had gailledg tZ.. the water. - trhe moMplaufible objeSion tothishypothefisis, thatiron gains the fame addition of weight, ad becomes the fame thing, whether it be Sheated ill contadc with fl:eam? or fur toursded by dephlogillicated ai-r. But from the preceding expe- ritnellts it appearsS that by far the greate{E part of the weight of dephlogiSicated air is waters and the fmall quantity-of acid that is itl st may well be fuppofed to be employed i forming the fsed vgr which ls always found in this procefs: Ur that thete is olle coulmon principle czf acidity? and that ali the acids ate cotlvertible irlto olle atlother (at leaR the nitrous acid into fised air) ss by no meaIls an zmprobal)le fuppoElti6Dns thougll re are 1lot yet in poffeilon.

AcidlFty, the ?O@X'OS of*X2zer, andPijAsgifan. z5g In my 1aI} Volume of Experitnetlts, -I recited thle parti:cu

lars of one, the relislt of urhich leemed to be ditEimilar tothis vvith the fcales of irotl and inflammable air > for heatitlg redprew cipirvze in inflatnmal)le air, I then foutld little ox no water; tut having uSed -more precautiolls I hawre fitce found it ill fuf -ficient quantity in this procefs, even though the itflammable air was previouflyiwell dried with fised ammoniace Itl this experiment I difcontinued the plocefs after three ounce meafures of air were abSorbedS leaving room itl the veXel, that the moiS ture might be more eaI;ly colleAed. With this precautionfi and warming the vefl"el7 I colleAed between an half and three- fourtlls of a graill of water

This experiment may be thought to be unfavourable to my preSerlt hypothefis7 as all water was carefully excluded, alld yet a fufficielat quantity was foutld in the procefs. But beildes taking into the account the water that is neceiary to conRitute theilflammableairX whymaylaot reXprecipZateS ill itS dryeR RateX be flppofed to contain; waterX as xtrell as the :fcales of ironS wlaich will bear Atly degree of heat without parting with it Ited precipitate is tnade by a liquid proceIi, and there fore the water, that may eluter into its COSpO5ltiOIl gS a cal uay quit it when it becomes a metalZ

I Shall take the liberty to obServe nfarther, that the dodritat of the decompoftion-of} tvatvr being fet afide tllat of ,thl@gsr (whichX in confequeIlce of the late experiments oll water9 has- been almoIt univerfully aI)atadotled) svs11 much better ftaladw its ground, as all the newly diScovered fads are nzore cafl3y ex plaiiled by the help of it.

If water be I10t clecompofed, botll metals a-d fulphie do certailily yleld iIaflatnnzable air, srrIlen Rearn i$ rnacle to pa'ls over thena in a redh2ate Theycatl-taotX thelcfore, ljeJimpl.4Jlbv

I36 Dr*0PRIESTERY'S ExperizenZ3 vd Obfersozzisus on Jicas, as the atatiphlogit}c theory makes them to be. A1CJI-ORI tlle falme tniLag that they have parted wi-th) Vi$e itlflarntnable-air (or rather fornethitlg that is left of illfl-airrlnai;)le air when vlae mvater is taketl flom it atld x^rhicls may as nvell be called 3?hlo gillon as at-sy thiog elte) tnay be trarlsferred to other fubRances5, ared tIlUS co;tltribute to forn] t3y of the uletlls:7 fulpllur, phoC phorus, or any tililg; eife tllat has becIl deeaned to colltaitl phlo gifiC3n. 'I'}lis l)tzllOgifiOn SlrO, I10 doubt, havillg weight, it perfeEiy correlpollds to the defi1wit-i:or< of a y:bJ?aezce havit3g celfltiliil affinities by meatls :c>f wh;lch it ixs trallsferrecl flom orae body to alaoth.er, as much as the difEerent acids.

If thR

- Aidity: the CampoJ*tian of MaferS vnd PDloe,on rS7 a>W,ero?s prgnciple may be giveru to that thitlg which, when it s ilacorporated with water, makes dephlog;Ricated air

As there is fiotnettlillg iEl dephlogiRicated air that feems to be the prillciple of usliverJ