418 COMPOUND SALTS 



1 atom sulphate of potash =11 



1 atom sulphate of ammonia = 8-25 



or any equimultiples of these weights in water, 

 evaporating the mixed solutions to the crystal- 

 lizing point. The salt is deposited in small 

 beautiful crystals, which crystallize in four-sided 

 prisms with square bases taste bitter specific 

 gravity 2*64. 13-68 grains dissolve in 100 wa- 

 ter of temperature 61. Their constituents are 



1 atom sulphate of potash 1 1 



1 atom sulphate of ammonia 7'125 



4 atoms water 4-5 



22-625 



Here the water of crystallization considerably 

 exceeds that of the salts of which it is composed. 

 >. Ammonio-sulphate of soda. The same 



sulphate of 



soda. process may be followed successfully in forming 

 this salt. The taste of this salt is pungent and 

 bitter. It crystallizes in oblique prisms with 

 rhombic bases. 



The crystals are not altered by exposure to 

 the air. Its constituents are 



1 atom sulphate of soda 9 



1 atom sulphate of ammonia 7'125 

 6 atoms water . . 6-75 



22-875 



In this salt the water of crystallization does not 



