‘32 ON THE FIRE-DAMP OF COAL-MINES, 
annually from this cause. From the state of the mines, part'- 
cularly in the accumulation of wastes, the collection of water, 
and the increasing depth of the workings, there is reason to 
fear, too, that such accidents will become more frequent. Hu- 
manity loudly calls, therefore, on every effort being made to 
obviate the calamity ; and even as a national concern, the im- 
mense loss of property in the mines, and the probability which 
has been suggested, that the working of them must ere long be 
abandoned, give to the subject the highest claims to considera- 
tion. 
I have to submit to the Society the account of a method 
which has occurred to me of lighting mines, not liable, like the 
common method, to the risk of kindling the fire gas, and which 
I trust may go far to obviate these unhappy occurrences. (Nete 
A.) 
The inflammable gas which is disengaged in coal-mines, it 
is well known, is carburetted hydrogen. In some situations it 
is much more abundant than in others. It has been supposed 
to be produced from the decomposition of water by coal, and, 
in particular, from the waste coal in the old workings, exposed 
to the action of humidity. It is possible that much of it may 
be from this source, and the fact, that it is most abundant in 
deep mines, where such wastes accumulate, is favourable to the 
opinion. This is not always, however, its origin. Much of it 
is disengaged from the solid coal as it is worked, and the sur- 
face of the wall of coal often continues to yield it from pores 
or fissures for weeks or months. It often, too, rushes sudden- 
ly, with great velocity, and in large quantities, from rents in 
the incumbent strata, or from vacuities within the mass of coal, 
in which it is pent up, apparently in a state of compression. 
The greatness of the mass of coal confining the gas more ef- 
rectually, or favouring the compression: with which it is retain- 
ed, 
