NEITHER POTASH NOR AMMONIA. 443 



and dried, weighed almost exactly 32*5 grains, 

 equivalent to 6 '5 grains of chromic acid. 



The liquid thus freed from chromic acid was 

 evaporated to dryness, and heated to redness in 

 a platinum vessel to get rid of any excess of 

 mercury that might have been added. It was 

 then dissolved in water, and the sulphuric acid 

 precipitated by muriate of barytes. The preci- 

 pitate, after being washed, dried, and heated to 

 redness, weighed 88*55 grains, containing 30 

 grains of sulphuric acid. But 30 grains of this 

 acid is equivalent to 6 atoms, requiring for satu- 

 ration 6 atoms or 36 grains of potash ; while the 

 6'5 grains of chromic acid require for saturation 

 6 grains of potash. It is obvious, from this ana- 

 lysis, that the constituents of this compound salt 

 are 



6 atoms sulphate of potash 66 

 1 atom chromate of potash 12-5 



78-5 



III. OF COMPOUND SALTS CONTAINING NEITHER 

 POTASH NOR AMMONIA. 



1. Carbo-tartrate of alumina-and-soda. When Carbo .tar- 

 solutions of tartrate of alumina and carbonate of alumina- 

 soda, each in the atomic proportions, are mixed a " 

 together, no precipitate falls ; but when the mix- 



