AnaVyus of the compound inflammable Gases. 285 



Transactions for 1803, p. 274. I believe, therefore, that 

 with an attention to those observances, which are required 

 hi all delicate experiments -on gases, and to the changing cir~ 

 cumstances of temperature and pressure, this apparatus is 

 fully adequate to the purpose for which it is intended. It will 

 be easy, however, for those who have the command of a suf- 

 ficient quantity of mercury, to adapt the apparatus to that fluid. 

 As an exemplification of the method of using it, in the sim- 

 plest possible case, I shall state the results of the combustion 

 of hydrogen gas. 



At the outset of the experiment, there was contained in the 

 receiver oo, a quantity of hydrogen gas, equal, when reduced 

 to a mean temperature and pressure, to 15*8 cubic inches* 



Of these, there remained unconsumed 2*5 



Hydrogen gas burned - - - - 13' 



In the receiver I were 49 cubic inches of oxygen gas, con- 

 sisting of - 33*5 oxygen, 15*5 nitrogen. 

 At the close of the experiment," 



there remained, in 6,43*5c.i ^27*25 16*25 



composed of 



he experiment, ~\ 

 1, in&,43*5e.i V27'i 



Cubic inches of oxyg-en ffasl a n . 

 • , ° •- >■ o*25 

 consumed J 



But estimating from the .first diminution (viz. 49-*-43 : 5) 

 only 5' 5 cubic inches of oxygen would appear to have been 

 absorbed ; and the nitrogen gas, by eudiomctrical experi- 

 ments, would seem to have been increased 0*75 of an inch. 

 As the hydrogen gas, however, had been prepared from 

 zinc and sulphuric acid with extreme caution, and did not 

 contain an appreciable quantity of common air, no such 

 addition of nitrogen could have taken place. The apparent 

 increase, then, may be fairly imputed to th§ escape of 0*75 

 of an inch of hydrogen gas, which is to be deducted from 

 the 13*3 cubic inches at the outset of the experiment : and 

 hence the real quantity consumed will be 13*3 — 0*75 = 12*55. 

 The true consumption, also, of oxygen gas was 5*50 4-0*75 

 = 6*25, or pretty exactly, as. it ought to be, half the bulk of 

 the hydrogen gas, which was actually bujned. 



An 



