266 FIXED ALKALIES AND ALKALINE EARTHS. 



the salt ceased to give out moisture. The loss 

 of weight was exactly 1*125 grain, which is 

 equivalent to 1 atom. The 7*&5 grains of an- 

 hydrous salt were dissolved in a minimum of dis- 

 tilled water, and the liquid was mixed with a 

 solution of 13*25 grains of chloride of barium. 

 After the sulphate of barytes had subsided, the 

 residual liquid was tested with sulphate of soda 

 and muriate of barytes ; but neither of these re- 

 agents produced any opalescence, showing that 

 it contained neither barytes nor sulphuric acid. 

 Consequently, the sulphuric acid in 7*25 grains of 

 anhydrous sulphate of lithia amounts to exactly 

 5 grains. The remaining portion of the salt be- 

 ing lithia, it is obvious that the true composition 

 of this salt is as follows : 



Sulphuric acid 5 or 1 atom 



Lithia . . 2-25 - 1 atom 

 Water . . 1-125 - 1 atom 



8-375 



Atom of Thus, the true atomic weight of lithia is 2*25, 

 and the sulphate contains an atom of each of its 

 constituents. 



iftSif 3 * ^ was ascer t ame d by Sir H. Davy, that li- 

 thia, like potash and soda, is a compound of a 

 white coloured metal, called lithium, and oxygen. 

 Though no experiments have been made to de- 

 termine the proportion of these two constituents, 

 there is no difficulty in ascertaining the true 



