288 SALTS 



This mineral, it is well known, lias a fine green 

 colour. The only metallic bodies which I can 

 find in it are, protoxide of manganese, which is 

 green, and perhaps a trace of iron. Is it pro- 

 bable that the green colour is furnished by the 

 protoxide of manganese ? 



Phosphate, 4,^ Phosphate of strontian. This salt is easily 

 obtained by mixing together solutions of phos- 

 phate of soda and nitrate of strontian in the ato- 

 mic proportions. The phosphate of strontian 

 precipitates in the state of a white powder, which 

 must be edulcorated, and dried in the open air. 

 The phosphate of strontian is a fine white light 

 powder, having scarcely any taste, and producing 

 no change on vegetable blues. 



When exposed to the greatest temperature of 

 the sand bath (about 600), it loses no weight. 

 10 grains of it, when exposed to a red heat, lose 

 O84 grain of weight, consisting of water driven 

 off. Hence, 11 '125 grains of the salt would 

 have lost O9345 grain. This approaches so 

 nearly to 1 atom of water, that I consider the 

 composition of the salt to be 



1 atom phosphoric acid 3-5 

 1 atom strontian . 6-5 

 1 atom water 1-125 



11-125 



^phosphate of strontian. This salt was 



1G 



