of charcoal and hydrogen. 151 
With seven volumes of mixed gases, of which the greatest 
part was carburetted hydrogen. Mr. Dalton has since fa- 
voured me with a specimen of oil gas prepared by himself, 
which contained in 100 parts, 40 of a gas condensible by 
chlorine ; and it appears from the table that oil gas, manu- 
factured on the large scale, may contain in 100 parts, 38 parts 
of a gas similarly characterized.* It is not improbable indeed 
that by a temperature carefully regulated, the whole of the 
aeriform fluids may be obtained from oil, of such quality as 
to be entirely condensible by chlorine ; and from the great 
superiority of the light which such a gas would afford, and 
the reduction that might be effected in the capacity of the 
gasometers, the discovery of a mode of producing it in this 
state, would be an important practical improvement. 
The inferences respecting the nature of the gas from oil, 
I reserve till after the account of the experiments on coal 
gas, as the same remarks, with some slight modifications, 
will apply to both cases. 
Experiments on the gas from coal. 
The numerous experiments and observations on the gas 
from coal, which I have already published, appear to me to 
preclude the necessity of going much into the subject on this 
occasion. What I have lately had in view, has been to render 
the analysis of this gas more complete, by a careful exami- 
* Since this Paper was written, I have received from Mr. Phillips a second 
specimen of oil gas prepared by Messrs. Taylo it. It contains in every 100 volumes, 
42 or 43 parts of gas condensible by chlorine ; but in other respects very nearly agrees, 
(inaking allowance for the greater proportion of that ingredient) with the gas de- 
scribed in the text. 
