Oh the ^antiiy afSulphuy in Sulphuric Am. J47 



lit ifii^ Rate, more than itf any other, Approach hea'fei''io whar may be termed, abfolutely; 



real acid. One hundred parts of calcined fulphate of lime contain therefore ' 

 Lime - - - . ^"7- 



Sulphuric acid - - - - 4^ 



.7 



100 



- By the former experiments (thofe made upon fulphur converted^ iftfo acidj and' theit 

 united to barytes) we had the quantity of fulphur, contained in fulphate of barytes. By- 

 the latter (thofe made bydireftly combining lime with fiilphuric acid) we had the propor"-^ 

 tion of realacid,. contained in calcined fulphate of lime. Gonfequently, by knowing the 

 ratio, > that falphate of barytes beai-stb'fiilph'ate of lime, with r^ard to thte- acid- irv eachj 

 we fhall arrive at thie knowledge of the quantity of fulphur contained in real fulphtaric acidi 

 For this purpofe, I attempted' to dilTolVe in watfer,' too parts of fdphatKfof limci' But 

 finding, in this method of proceeding, a confiderable inconvenience arifing from the great 

 quantity of liquor, neceffary to efFedV the folutibn of that fait, I had' fccourfe to the fol- 

 io-wing expedient. Upon 1 00 graina of 'calcined" fdlphate of- lime,' P poured fome oxalii 

 acid, which at-trafts the bafis'^With "an affiitity fui)e'riGr to that exerciftd y;^-'fulphurie acids 

 Oxalate of lime was here formed^ but oxalate of lime is foluble in a very fmall excefs of 

 any acid. A little muriatic acid operated a complete ' folution ; and thus" d'great quantity 

 of fulphate of lime required but Httle water to diflblve it. Into this liquor, muriate of 

 barytes was poured, and fuffered to remain fome time, gently heated; By thefe meansj 

 any oxalate of barytes, "that might have befetiMi-nied," was retained in (blution by ihe-ori-- 

 ginal excefs of acid; and the intire quantityof'fiilijhate Of barytes was ^d^pofited.- Of the 

 exaftnefs of all thefe methodswhich lufed, as the inftruntents by which r-aftertaiiied thefe 

 refults, I convinced myfelf by various preliminary experiments. After the ufual filtratiow 

 wafhingand drying at the gende heat of a fand- bath, I "obtained m one experiment- 1 85 j ia- 

 hnother r83, and laftly, in ahother 180. This difference does not tlxceed ' the limits of 

 what all' perfons, converfant in analytic chy'm'iftfy,^. Will allow to experiment's of this na- 

 ture. We may therefore take 183 as the mdah'^irbportion ;- confequehtly we fhall fay^ 

 that 183 of fulphate of barytes contain the fame qdimity of fulphuric acW, as ido of4aIi 

 phateoflime; and 183:43 :: 100:23.5. Th'erefore 23.5 is the proportion of acid ia- 

 100 of fulphate of barytes. But -wc have before ften, thar 14.5- of fulphur, .acidified by ■ 

 nitric acid, form that portion of fulphuric acid contained in xoo of fulphate of barytes : 

 viz. 23.5. We mufl: now fay, that 23.5 : 14.^ : : 100 :6i.5, and the fourth term will be 

 the proportion of fulphur':^ 6i.j^, \^liich'ctfriib5fi^4 xi^ifh '^8.^ of oxi^en^vriU form; loo^f. 

 real fulphuric acid. — --'n j:j ii • ..^ :• ., :. v - .,,:;: --.l y> ■ -..y,- 



In neither of the proportions, whether it be of the acid contained iii the fait, or of the- 

 combuflible bafis contained in the acid, do I agtee with the two chymifts whom I hava 

 quoted. This juflly excited fome doubts in my mifid, and led me to repeat my experi- 

 ments. Nor ftiouid I yet be thoroughly fatisfied, if I could not, upon other grounds, 



Y y z. thaiL 



