426 Experiments on the Gas from Coal. 
measures having consumed very nearly 
twice their bulk of oxygen, and given an 
equal volume of carbonic acid. We may, 
therefore, consider the early products of the 
gas from cannel as a mixture of about one 
volume of olefiant gas and four volumes of 
carburetted hydrogen.* 
The early product of gas from Clifton coal 
does not admit of being thus theoretically 
resolved into a mixture of olefiant and car- 
buretted hydrogen gasesonly. For after de- 
ducting from the oxygen consumed (164 
measures) that spent in saturating the olefiant 
- gas (10x3=30) we have only 134 measures 
of oxygen left for the combustion of 90 
measures of inflammable gas. These 90 mea- 
sures, it appears, afford 91—20=71 measures 
of carbonic acid. This portion of the gas 
does not, therefore, answer to the characters 
of carburetted hydrogen, since it neither gives 
an equal volume of carbonic acid, nor con- 
* T am perfectly aware of the importance of taking the 
specific gravity of mixed gases, as one datum for deter- 
mining their proportion in any mixture; but I was pre- 
vented from ascertaining it in these experiments by the 
state of the necessary apparatus, which was found, from 
long disuse, to have become unfit for the purpose. So far 
as respects the practical objects of this paper, the omis- 
sion is of no consequence, — 
