1 80 Dr. Bache on the Anali/sis of certain Gaseous Mixtures. 



Method of ascei-taining the Proportions of Bihydrogwet of Car- 

 bon and Carbonic Oxide in a Mixture of those Gases, provided 

 no other inflammable Gas bcprescnt. Bj/ Franklin Bache, 

 M.D., S,c 8sc. Sfc. 



I will here subjoin an excellent method of ascertaining the 

 proportions of bihydroguret of carbon and carbonic oxide, in 

 a mixture of those gases, which has been ingeniously and cor- 

 rectly suggested by my friend Dr. Bache. 



" The proportion of carbonic oxide in a mixture of this gas 

 and bihydroguret of carbon, may be calculated from the quan- 

 tity of oxygen consumed by them when exploded, in the fol- 

 lowing manner. 



" If we suppose a gas to be all bihydroguret of carbon, it 

 will consume twice its volume of oxygen : if, on the other hand, 

 it be all carbonic oxide, it will require half its volume for com- 

 plete combustion. It must be evident, therefore, that a mix- 

 ture of these gases will consume a volume of oxygen, inter- 

 mediate between half the volume and twice the volume of the 

 mixture; and that whatever may be the volume of the oxygen 

 consumed, it will bear a constant proportion to the carbonic 

 oxide present. 



" Reasoning from the analysis of the pure bihydroguret, 

 which requires twice its volume for complete combustion, it 

 must be apparent that the introduction of the least portion of 

 carbonic oxide will necessarily diminish the quantity of the 

 oxygen consumed. Now it will be found that this diminution 

 of the quantity of the oxygen required, bears to the carbonic 

 oxide present the constant ratio of 3 to 2. Hence we have 

 this proportion : — 



" As 3 is to 2, 

 So is the deficit of oxygen above alluded to, to the carbonic 

 oxide present. 



" This mode of calculating the carbonic oxide in the mix- 

 ture supposed, may be expressed in an algebraic formula, as 

 follows : — 



" Let M = volume of the gaseous mixture, and 

 O = volume of oxygen consumed. 



Then ~- = volume of carbonic oxide present. 



3 ^ 



And as carbonic oxide contains half its volume of oxjgen, then 



— ^— = volume of oxygen in the carbonic oxide." 



This method is evidently preferable in the case of a mixture 

 known to consist of pure bihydroguret and carbonic oxide : 

 but unfortunately it is inapplicable if hydrogen be present in 



any 



