358 SALTS 



when exposed to a red heat. Hence, the salt is 

 anhydrous, and its constituents are 



1 atom chromic acid . 6*5 

 1 atom oxide of zinc 5-25 



11-75 



Acetate, g t Acetate of zinc. This salt crystallizes in 

 large very oblique rhombs. It has a silky lustre, 

 and, indeed, bears a very close resemblance to 

 talc in its appearance ; when kept for some time 

 it is apt to lose a little of its acid. Its constitu- 

 ents, supposing it examined when in a state of 

 purity, are 



1 atom acetic acid . 6*-25 



1 atom oxide of zinc . 5-25 

 7 atoms water . 7-875 



39-275 



Q. Oxalate of zinc. This salt may be ob- 

 tained by mixing together solutions of sulphate 

 of zinc and oxalate of ammonia in the atomic 

 proportions. For a few seconds the mixture 

 continues transparent, but it gradually becomes 

 muddy, and deposites oxalate of zinc in abun- 

 dance : the decomposition is complete, for no 

 traces of oxalic acid or oxide of zinc can be 

 found in the supernatant liquid. 181'&5 grains 

 of sulphate of zinc and 88'75 grains of oxalate 

 of ammonia, gave 118 grains of oxalate of 



