OF MAGNESIA. 299 



t 



It is scarcely possible to drive off the whole wa- 

 ter, without affecting the acid, which is much 

 more easily decomposed than either acetic or 

 oxalic acid. It was analyzed by keeping 16*25 

 grains of it in a low red heat till the carbonate 

 of lime became white. It weighed 6-25 grains 

 very nearly. 



From the preceding list it appears, that many 

 of the salts of lime are anhydrous. The water 

 of crystallization, when it exists, amounts to 2, 

 3, 4, or 6 atoms. No salt of lime is known 

 which contains more than 6 atoms. 



7. SALTS OF MAGNESIA. 



1. Sulphate of magnesia. This well known sulphate, 

 salt crystallizes in right square prisms, and is not 

 altered by exposure to the air. Its constituents 



are 



1 atom sulphuric acid 5 

 1 atom magnesia 2-5 



7 atoms water . 7*875 



15-375 



2. Nitrate of magnesia, though it crystallizes Nitrate, 

 readily enough, is so deliquescent a salt that it is 

 very difficult to obtain it in a state proper for 

 analysis. 16 grains of the crystals, dried by 

 pressure between folds of blotting paper, were 



