SILICON. 167 



cic acid. Thus, all the parts of this experiment 

 confirm eac h other, and show that borax is a 

 compound of 



2 atoms boracic acid 6 



1 atom soda . 4 

 8 atoms water . 9 



19 



8. Arfwedson has analyzed boracite by aofboradte. 

 similar process, and it follows from his analysis, 

 that the mineral is a biborate of magnesia, 

 and consequently a compound of 



2 atoms boracic acid 6 



1 atom magnesia 2-5 



8-5 



This salt is perfectly anhydrous. 

 SECT. III. 



OF THE ATOMIC WEIGHT OF SILICON. 



THOUGH the experiments of Sir H. Davy have 

 satisfied chemists that silica is a compound of 

 oxygen, and a dark coloured combustible sub- 

 stance, like carbon or boron, to which the name 

 of silicon or silicium has been given ; and though 

 Berzelius has obtained silicon in a separate 

 state } yet as silica is the only known compound 



L 4 



