178 Dr. Henry on the Aeriform Compounds [Sept, 



As an illustration of the method of investigating the propor- 

 tions of mixtures of the three last gases, we may take the 

 instance of a mixed gas, free from defiant gas, of specific gra- 

 vity *534, of which 100 volumes consume 110 of oxygen, and 

 afford 70 of carbonic acid, the diminution of the whole 210 after 

 firing being 140 volumes. Now it must be obvious from inspec- 

 tion of the Table, that the 70 parts of carbonic acid cannot all 

 have resulted from the combustion of carburetted hydrogen, 

 since, for the saturation of 70 measures of that gas, 140 of oxy- 

 gen would have been required, whereas only 110 have been 

 expended. We may, therefore, safely infer the presence of car- 

 bonic oxide, a gas which, by combustion, gives its own volume of 

 carbonic acid, with the expenditure of only half its volume of 

 oxygen. The specific gravity of the specimen being lower than 

 that of carburetted hydrogen, indicates also an admixture of 

 simple hydrogen gas; and of this the proportion must necessa- 

 rily be considerable, to countervail the weight of the heavy 

 carbonic oxide. The following proportions of the three gases 

 will be found to coincide with the properties of the mixture. 



Consume ox. Give carb. ac. fi s' 



40 vols, of carb. hydrogen ... 80 40 80 



30 vols, of carb. oxide 15 30 ...... 15 



30 vols, of hydrogen gas 15 45 



"lOO 110 70 140 



No reliance, however, can be placed on the accuracy of such 

 estimates, unless the specific gravity of the specimen agrees 

 with that of the hypothetical mixture, as deduced from the 

 proportion of its ingredients. But when this coincidence takes 

 place, we have all the evidence, which the subject at present 

 admits, of the nature of the mixture ; and as this agreement 

 between experiment and calculation was found to take place 

 very nearly in all the instances comprehended in the two fol- 

 lowing Tables, we may consider the numbers composing them, 

 as expressing, with sufficient exactness, the relative proportion 

 of different gases in the residues of oil and coal gas left by the 

 action of chlorine. 



Table IV. — Shmring the Composition of 100 Volumes of the Gas 

 remaining after the Action of Chlorine on Oil Gas. 



