346 SALTS 



third the weight of the salt ; which exceeds 8 

 atoms a little. Probably the excess, which a- 

 mounts to about half an atom, was only mechan- 

 ically mixed with the salt and not chemically 

 combined. 



8. Chromate of cobalt. This salt was obtained 

 by mixing solutions of chromate of potash and 

 nitrate of cobalt together. The chromate gra- 

 dually fell down, of a reddish brown colour ; it 

 had no taste, and produced no change on vege- 

 table blue colours. 12-85 grains of it when ex- 

 posed to a red heat, assumed an olive green co- 

 lour, and lost 2-1 grains 'of its weight. Hence, 

 the constituents of the salt are 



1 atom chromic acid 6*5 



1 atom oxide of cobalt 4*25 



2 atoms water 2-25 



13-0 



Oxaiate, 9- Oxalate of cobalt. This salt is easily ob- 

 tained by mixing together the solutions of ni- 

 trate of cobalt and oxalate of ammonia. The 

 precipitate is to be collected on a filter, well 

 washed and dried in the open air. It is a light 

 red powder, destitute of taste, insoluble in water, 

 and incapable of altering the colour of vegetable 

 blues. 11 grains of this salt, when heated upon 

 the sand bath, lose 2'25 grains of water; and 

 leave, when calcined, 4-25 grains of protoxide of 

 cobalt. Hence, the constituents are 



