1 82 1 .] of Charcoal and Hydrogen . 1 79 



Table V. — Showing the Composition of 100 Volumes of the Gas 

 remaining after the Action of Chlorine on Coal Gas. 



It appears from the two foregoing Tables, that the portion of 

 oil gas and coal gas, which is not condensible by chlorine, is 

 in every case a mixed gas, consisting in most instances of car- 

 buretted hydrogen, carbonic oxide, and hydrogen, with a little 

 azote, part of which may be traced to the impurity of the chlo- 

 rine. In the best specimens of oil gas, the carbonic oxide is in 

 greater proportion than in the best kinds of gas from coal, and 

 the carburetted hydrogen is most abundant in the latter gas. 

 This, however, is more than compensated, so far as their illumi- 

 nating power is concerned, by the greater richness of the aeriform 

 products of oil in that denser species of gas, which is separable 

 by chlorine. The proportion of hydrogen, both in oil gas and 

 coal gas, appears to increase as they are formed at a higher 

 temperature, and is always greatest in the latter portions of the 

 gas from coal. But no instance has ever occurred to me of a 

 gas obtained from oil or from coal, which, after the action of 

 chlorine upon it with the exclusion of light, presented a resi- 

 duum at all approaching to simple hydrogen gas ; nor do I 

 believe that such a gas can be generated under any circum- 

 stances of temperature, by which the decomposition of coal or 

 of oil is capable of being effected. 



Inferences respecting the Composition of that Part of the Gas 

 from Coal and Oil, which is condensed by Contact with 

 Chlorine. 



When a given volume of a mixture of defiant and carburetted 

 hydrogen gases is fired with oxygen, and an equal volume of 

 the same mixture is first deprived of olefiant gas by the action 

 of chlorine, and then fired with oxygen, it must necessarily 

 happen that the excess of oxygen spent in the first combustion, 

 above that consumed in the second, will be three times the 

 volume of the olefiant gas, and that the excess of carbonic acid 

 formed in the first experiment above that generated in the 

 second, will be double the volume of the olefiant gas. A 

 remarkable anomaly, however, was, during the last summer, 

 observed by Mr. Dalton in the results of the combustion of a 

 quantity of gas, which he had himself prepared from oil. One 

 volume was found to consume three volumes of oxygen, and to 

 yield little short of two volumes of carbonic acid, in those 



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