ANAJ.YSJS OF SULPHATE OF BARYTES. 181 



sulphate of lime afforded 183 grains of sulphate of barytes sulphate of ba« 

 dried at the gentle heat of a sand bath ; but the sulphate of ba- 2^/ ° re 

 rytes dried at this heat contains still near 3 per cent of water, 

 which deducted leaves 178*5 grains. If we say therefore, 

 that 178'5 grains of sulphate of barytes contain the same 

 quantity of sulphuric acid as 100 grains of sulphate of 

 lime, and that 100 grains of sulphate of lime contain 58 

 sulphuric acid ; we have for the composition of sulphate of 

 barytes, sulphuric acid 32*5, barytes 67*5; which differs 

 only half a grain per cent from what I have myself ob- 

 tained. 



Still farther to confirm the preceding results, I made the Farther con- 

 following experiments. Into a solution of nitrate of barytes rnaUons ° 

 1 poured 100 grains of sulphuric acid (the spec. grav. of 

 which I omitted to note). Care was taken to have an ex- 

 cess of nitrate of barytes, and the solution was slowly eva- 

 porated down to dryness. The precipitate carefully washed 

 from the remaining nitrate, dried, and calcined, weighed 

 231 grains. 



An equal weight of the same sulphuric acid was poured 

 into a solution of acetate of lime, in which the latter was 

 in excess. After gradual evaporation to dryness, the ace- 

 tate of lime was separated by repeated washing with alco- 

 hol, and the sulphate of lime dried and calcined. It 

 weighed 133 grains. 



Lastly, 100 grains of sulphuric acid were poured into a 

 solution of acetate of lead in excess, and the precipitate 

 carefully separated, washed, and dried. It weighed 296, 

 grains. 



From these experiments it appears, that 231 grains ofsul- R^itsof 

 ( phate of barytes, 133 grains of sulphate of lime, and 296 grains these experi- 

 of sulphate of lead, contain equal quantities of sulphuric raeats ' 

 acid; and if in estimating the real quantities of acid they 

 contain, we adopt Klaproth's analysis of sulphate ^f 

 lead as the standard, to which to refer them, we shall have 

 29.6 grains of sulphate of lead, containing 78*4 grains of sul- 

 phate of acid, or 26*5 per cent; 



231 grains of sulphate of barytes, containing 7S'4 grains of 

 sulphate of acid, or 33*9 per cent; 



133 grains 



