[ 240 ] 



plete folution; and thus a great quantity of fulphate of lime 

 required but little water to diflblve it. Into this liquor, mu- 

 riate of Barytes was poured, and fufFered to remain fome time, 

 gently heated. By thefe means, any oxalate of Barytes, that might 

 have been formed, was retained in folution, by the original ex- 

 cefs of acid ; and the entire quantity of fulphate of Barytes was 

 depofited. Of the exadnefs of all thefe methods, which I ufed, 

 as the inftruments by which I afcertained thefe refults, I con- 

 vinced myfelf by various preliminary experiments. After the 

 ufual filtration, wafhing and drying at the gentle heat of a 

 fand-bath, I obtained in one experiment 185, in another 183, 

 and, laftly, in another 180. This difference does not exceed the 

 limits of what all perfons, converfant in analytic chymiftry, 

 will allow to experiments of this nature. We may therefore 

 take 183 as the mean proportion; confequently, we (hall fay, 

 that 183 of fulphate of Barytes contain the fame quantity of ful- 

 phuric acid, as 100 of fulphate of lime ; and 183 : 43 :: 100 : 23.5. 

 Therefore 23 5 , is the proportion of acid in 100 of fulphate of 

 Barytes. But we have before feen, that 14.5 of fulphur, aci- 

 dified by nitric acid, form that portion of fulphuric acid con- 

 tained in 100 of fulphate of Barytes: viz. 23.5. We muft 

 now fay, that 23.5 : 14.5 :: 100 : 61.5, and the fourth term will 

 be the proportion of fulphur = 61.5, which combined with 38.5 

 of oxygen will form 100 of real fulphuric acid. 



In 



