132 EXPERIMENTS ON SULPHURIC ACIt>< 



Expts. of Taf- The method which I had ufed to afcertain the quantity of 

 Md rt GI h ton! rd, fuJ P hurin an ore, had been pradifed by Taflaert, (Annates de 

 Chimie, No. 82 : Analyfis of Cobelt from Tunaberg) but he 

 calculated according to the proportions of Lavoiiier and of 

 Fourcroy. In another paper by Thenard, (Annates de Chimie, 

 No. 96.) he ftates the proportions of fulphuric acid, obtained 

 by treating fulphur with nitric acid, to be 



Sulphur - 55.56 



Oxygen - ... 44.44 



100.00 



but in the extract given by Guyton in that No. of the Annates 

 de Chimie, the mode of operation is not defcribed. Calcined 

 fulphate of barytes is eftimated in the fame paper to contain 



Barytes - - - - - 74.82 

 Sulphuric acid - - - - -25.18 



100.00 

 which proportions are as near to what I had found as can be 

 expe&eo ; for fulphate of barytes does not contain more than 

 3 per cent, of water of cryftallization, and they muft be de- 

 ducted from the quintal. 

 From the deter- Having determined with accuracy the proportion of acid in 

 Mid a m°an fnS! an ? inr ° Iubie ^lphate, it is eafy to proceed to the determina- 

 luble fulphate, tion of that contained in any other fulphate. The docimaftic 

 it becomes eafy art or ana iytic chymiftry in general, cannot however expeft to 

 others. derive fuch advantages from the knowledge of foluble falts, as 



of thofe, which, from their infolubility, may be ufed with ac- 

 curacy in delicate experiments to determine the proportions of 

 the conftituent parts of bodies. But if, with this mode of ope- 

 rating, we compare the quantities of real acid, faid (in thofe^ 

 excellent tables with which Mr. Kirwan has enriched the fci- 

 ence) to be contained in fulphuric acid of different fpecific gra- 

 vities, they will ferve as proofs of their mutual validity ; and 

 perhaps demonftrate, that fulphuric acid, as well as water, 

 and fome other bodies, may of itfelf enjoy liquidity, at the 

 temperature and preflure which aft upon our globe. 



SCIENTIFIC 



