228 ACIDIFIABLE COMBUSTIBLES. 



posed each other. The hydrogen of the gas had 

 united to the oxygen of the oxide, and formed 

 wa ter while the selenium and the silver combin- 

 ing together, formed the seleniet of that metal. 

 Seleniet of silver being a compound of 1 atom 

 silver and i atom selenium, and water of 1 atom 

 oxygen and 1 atom hydrogen, it is evident, that 

 selenietted hydrogen must be a compound of 1 

 atom hydrogen and 1 atom selenium. Its con- 

 stituents, then, from the preceding analysis, must 

 be 



Selenium 4-9343 

 Hydrogen 0425 



But if 7 be the atomic weight of selenic acid, it 

 is obvious that the atomic weight of selenium 

 must, in fact, be 5 instead of 4'9343 ; for sele- 

 nic acid must be a compound of 



1 atom selenium 



2 atoms oxygen : 



And its weight could not be 7> unless the weight 

 of selenium were 5. 



The true composition of selenietted hydro- 

 gen, then, must be 



Selenium 5 or 40 

 Hydrogen 0-125 - 1 



5-125 



And the atomic weight of this gas must be 



