MRS. B.
A gas can be destroyed only by condensing it to a liquid or solid state; when this takes place suddenly, the gas, in assuming a new and more compact form, produces a vacuum, into which the surrounding air rushes with great impetuosity; and it is by that rapid and violent motion that the sound is produced. In all detonations, therefore, gases are either suddenly formed, or destroyed. In that of gunpowder, can you tell me which of these two circumstances takes place?
EMILY.
As gunpowder is a solid, it must, of course, produce the gases in its detonation; but how, I cannot tell.
MRS. B.
The constituents of gunpowder, when heated to a certain degree, enter into a number of new combinations, and are instantaneously converted into a variety of gases, the sudden expansion of which gives rise to the detonation.
CAROLINE.
And in what instance does the destruction or condensation of gases produce detonation?
MRS. B.
I can give you one with which you are well acquainted; the sudden combination of the oxygen and hydrogen gases.