CHAP. VI. 



OF THE ATOMIC WEIGHTS OF THE ACIDI- 

 FIABLE COMBUSTIBLES. 



THE simple bodies, which I have distinguished 

 by the name of acidifiable combustibles, are the 

 nine following : 



I have already treated of hydrogen in the first 

 chapter of this work. I shall endeavour in this 

 chapter to establish the atomic weights, and to 

 point out the principal combinations of the re- 

 maining eight. These bodies differ from all the 

 other combustible substances in the property 

 which they have of entering into gaseous com- 

 pounds, either with hydrogen gas or fluoric acid, 

 while none of the other combustible bodies enter 

 into any gaseous combination whatever. An 

 accurate knowledge of their atomic weights will 

 be found important, not merely as connected 

 with chemical analysis ; but because it throws 

 an important light on the relation between the 

 atomic weight and the specific gravity of gaseous 

 bodies. 



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