DURHAM AND NORTHUMBERLAND. IQ?

in a coal mine, wherein all implements and-requisites are exposed to the roughest and mostdestructive treatment; of this however, Sir H.Davy ought to be well convinced. It is a sub-ject upon which I shall say something more in afuture page ; at present we will suppose it allcorrect.

No difference was noticed in these experi-ments from the effects of the metallic tubes,gauze, &c. becoming heated; but it is pre-sumed, according to some experiments Dr.Clanny made from Grotthus, who discoveredthat inflammable mixtures when expanded tosix times their volume were deprived of explo-sive power, there is some sensible difference.

It will be unnecessary to recapitulate thegreat diversity of experiments made by SirH. Davy, further than I have already done, asmany of them may probably be found merelytheoretical, in regard to fire-damp, when prac-tically adopted in a colliery. Sir H. Davy sug-gests the use of a fire made of charcoal in thoseparts of a mine where the air is explosive, as itburns without flame. But surely he could notbe ignorant that in this situation the great ab-sence of vital air would make it difficult for therespiration of miners, and as charcoal is themost greedy of all other things in consumingoxygen, exclusive of the increase of carbonic