9% On Olefiant Gas. [Jan. 



jiecessaiy, and two volumes of carbonic acid result from their 

 joint action. A volume and a half more of oxygen, therefore, is 

 consumed in the present case, and an additional volume of car- 

 bonic acid produced from it, from which we may infer that the 

 new gas contains an atom each of carbon and of hydrogen more 

 than exists in an equal bulk of olefiant gas, and that its specific 

 gravity, therefore, will be greater by the addition of the respec- 

 tive specific weights of those elements. It has been already 

 mentioned that the specific gravity of olefiant gas is '972, and 

 it is well known, tl^at this gas is formed of one atom of carbon 

 and one atom of hydrogen. The specific gravity of vapour of 

 carbon, as has been shown by Dr. Thomson in a former volume of 

 the Anmls, is -4166, and of hydrogen -0694 ; but -4166 + '0694 

 = '486, which is only one half of the specific gravity assigned. 

 It must be inferred, therefore, that in the constitution of olefiant 

 gas, two volumes of vapour of carbon, and two volumes of hydro- 

 gen, are condensed into one volume — a deduction which the 

 phenomena attending the explosion of this gas with oxygen 

 amply confirm. 



It was before stated, that three volumes of oxygen are required 

 for the above purpose, and that two volumes of carbonic acid 

 are the gaseous result : to explain which it is necessary to assume 

 that two volumes of carbon are present to saturate two of the 

 volumes of oxygen, and produce the two volumes of carbonic 

 acid ; and that there are also two volumes of hydrogen in com- 

 bination to unite with the remaining volume of oxygen, and form 

 water. In conformity with these views, the new gas will, of 

 course, be compounded of three volumes of vapour of carbon and 

 three volumes of hydrogen condensed into one volume ; and its 

 specific gravity, as already stated, will be the specific gravity of 

 olefiant gas, augmented by the specific gravity of each of the 

 additional elements of which it is composed, or -972 + '4166 

 + -0694 = 1-458. 



Proceeding upon these data, and supposing the 38 volumes 

 of condensible gas, which formed the subject of Dr. Henry's 

 experiments, to be '* a mixture of olefiant gas with a heavier or 

 more combustible gas," as he suggested, and that this heavier or 

 more combustible gas is the one above described, the proportion 

 of the two necessary to produce a specific gravity of 1*395, as 

 deduced from his experiments, will be 100 volumes of the heavy 

 olefiant gas, if it may be so called, and 1-49 volume (very 



nearly) of the hght olefiant gas; for'^^-^-^ = 1-395, from 



whence x = ^ = -14893, 



It may be concluded from the foregoing observations, and, 

 perhaps, satisfactorily, that the gaseous body which has been 

 discovered by Dr. Henry among the aeriform products from oil 

 and pit coal is not *' a new gas, sui generis, consisting of hydro- 



