SALTS 



] atom phosphoric acid 3-5 



1 atom alumina 2-25 



3 atoms water 3-375 



9-125 



6. Arsemate of alumina. This salt was ob- 

 tained by mixing together solutions of alum and 

 arseniate of soda in the atomic proportions. It 

 is a white, tasteless, insoluble powder, not un- 

 like phosphate of lime ; but it strongly reddens 

 vegetable blues. 



16-75 grains of this salt being exposed to a 

 red heat, lost 6*7^ grains of its weight, and still 

 reddened vegetable blues. Hence, the consti- 

 tuents of the salt are 



1 atom arsenic acid 7'75 

 1 atom alumina 2-25 



6 atoms water 6*75 



16-75 



7- Chromate of alumina. This salt being 

 very soluble in water, I could not form it by 

 double decomposition ; but when chromic acid 

 and hydrate of alumina are long digested to- 

 gether, a fine yellow solution is obtained, which, 

 however, I did not succeed in analyzing in a 

 satisfactory manner. I ascertained merely that 

 the salt is soluble in water, and that it has a yel- 

 low colour. 

 Acetate, 8. Acetate of alumina. This salt was formed 



