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bottle, produced a slight whistling sound;1 part of gas with 8 parts of air, rather alouder sound: 1 part with 10, 11, 12, 13and 14 parts, still inflamed, but the violenceof combustion diminished. In 1 part ofgas and 15 parts of air, the candle burntwithout explosion with a greatly enlargedflame; and the effect of enlarging the flame,but in a gradually diminishing ratio, wasproduced as far as 30 parts of air to 1 of gas.

The mixture which seemed to possessthe greatest explosive power, was that of 7or 8 parts of air to 1 of gas; but the reportproduced by 50 cubical inches of this mix-ture was less than that produced by one-tenthof the quantity of a mixture of 2 parts ofatmospherical air and 1 of hydrogene.

It was very important to ascertain thedegree of heat required to explode thefire-damp mixed with its proper proportionof air.

I found that a common electrical sparkwould not explode 5 parts of air and 1 offire-damp, though it exploded 6 parts of airand 1 of damp: but very strong sparks fromthe discharge of a Leyden jar, seemed tohave the same power of exploding different