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no marks of the presence of olefiant gas orhydrogene; and the residuum produced by-detonation with chlorine showed them tobe tree from carbonic oxide.

It is evident, then, that the opinion formedby other chemists respecting the fire-dampis perfectly correct; and that it is the samesubstance as the inflammable gas of marshes,the exact chemical nature of which was firstdemonstrated by Mr. Dalton ; and that itconsists, according to my view of definiteproportions, of 4 proportions of hydrogenein weight 4, and I proportion of charcoalin weight 11.5.

I made several experiments on the com-bustibility and explosive nature of the fire-damp. When 1 part of fire-damp wasmixed with 1 of air, they burnt by theapproach of a lighted taper, but did notexplode; 2 of air and 3 of air to 1 of gasproduced similar results. When 4 of airand 1 of gas were exposed to a lightedcandle, the mixture being in the quantityof 6 or 7 cubical inches in a narrow neckedbottle, a flame descended through the mix-ture, but there was no noise: i part of gasinflamed with 6 parts of air in a similar