286 SALTS 



even the precipitated salt is perfectly anhydrous, 

 if it be dried in a temperature of 212. Its con- 

 stituents are 



1 atom sulphuric acid 5 

 1 atom strontian 6-5 



11-5 



When the precipitated sulphate of strontian is 

 dried in the open air, it retains about yfeth part 

 of its weight of water mechanically lodged 

 among its particles. This amounts to about 4th 

 of an atom, 



Nitrate, >. Nitrate of strontian. Of this salt there are 

 two species, distinguished from each other by 

 the presence or absence of water of crystalliza- 

 tion. 



Anhy. (i.) Anhydrous nitrate of strontian crystal- 



lizes in dodecahedrons composed of two six-sided 

 pyramids applied base to base. The apices of 

 the pyramids are deeply truncated, so as to give 

 the crystal the appearance of a six-sided table 

 with bevilled edges ; it is not altered by expo- 

 sure to the air. Its constituents are 



1 atom nitric acid 6- 7 5 



1 atom strontian 6-5 



13-25 



Hydrous. (g.) Hydrous nitrate of strontian is a trans- 

 parent salt, crystallized in acute rhomboids. Its 



