382 SALTS 



the same as the preceding, only it contains but 

 half as much water. 



1 atom arsenic acid 7*75 



2^ atoms oxide of copper 12-5 

 3 atoms water . . 3-375 



23-625 



(5.) The fifth variety of Chenevix is the 

 Imzenerz of mineralogists. It has a fine grass 

 green colour, a specific gravity of 2'881, and its 

 primary form is an obtuse octahedron with a 

 rectangular base ; it contains twice as much 

 base and thrice as much water as the third va- 

 riety of Chenevix, being composed of 



] atom arsenic acid 7 75 



5 atoms oxide of copper 25 

 18 atoms water . . 20'25 



53 



In this last salt, however, the water found by 

 Chenevix approaches nearer to 17 than to 18 

 atoms. 



chromate, 6. Chromate of copper. This salt was ob- 

 tained by mixing together solutions of chromate 

 of potash and muriate of copper. A fine buff 

 coloured precipitate with a shade of dark red 

 fell, which was collected on a filter, washed and 

 dried in the open air at a temperature of be- 

 tween 70 and 80, This powder appeared at 



