OF AMMONIA. 



10. Binarseniate of ammonia. This salt was 

 obtained by dissolving crystallized arseniate of 

 ammonia and dry arsenic acid in water, each in 

 the atomic proportions. The solution being suf- 

 ficiently concentrated and set aside, large crys- 

 tals of binarseniate of ammonia were deposited. 

 They were opaque white irregular rhomboids ; 

 the taste of the crystals was saline, astringent, 

 and acid, and they strongly reddened vegetable 

 blues. 



19*87o grains of this salt were dissolved in 

 water, and mixed with a solution of 41*5 grains 

 of nitrate of lead. After the arseniate of lead 

 had precipitated, the residual liquid was neither 

 affected by glauber salt nor nitrate of lead. 

 Hence, we see that 19'S7<5 of this salt contain 

 just 2 atoms of arsenic acid. The constituents 

 of the salt consequently are 



2 atoms arsenic acid 



1 atom ammonia 



2 atoms water 



19-875 



11. Chromate of ammonia. This salt is not 

 easily obtained in a state of purity, from the 

 great tendency which it has to part with half of 

 its ammonia during its concentration. It may, 

 however, be procured in a solid state by the fol- 

 lowing process : supersaturate chromic acid with 

 ammonia, and place the solution (which should 



Q-t 



