BARYTES AND BARIUM. 26? 



composition of lithia, now that we know the 

 atomic weight of this alkali and of oxygen. 

 Potash and soda are each of them compounds of 

 1 atom of oxygen, with 1 atom of potassium 

 and sodium respectively. We shall find that the 

 composition of barytes, strontian, lime, and mag- 

 nesia, is quite similar. It is reasonable to con- 

 clude from this, that lithia is likewise a com- 

 pound of 1 atom oxygen and 1 atom lithium ; 

 consequently, an atom of lithium must weigh 

 1-25, and lithia must consist of 



1 atom lithium 1*25 

 1 atom oxygen 1 



2-25 



SECT. IV. 



OF THE ATOMIC WEIGHTS OF BARYTES AND 

 BARIUM. 



BARYTES has been employed in many of the pre- 

 ceding sections to determine the atomic weight 

 of different bodies, in consequence of the pro- 

 perty which it has of forming an insoluble com- 

 pound with sulphuric acid. It has been already 

 explained, that sulphate of barytes is a compound 

 of 



