CAROLINE.
Is not that the salt with which gunpowder is made?
MRS. B.
Yes. Gunpowder is a mixture of five parts of nitre to one of sulphur, and one of charcoal.—Nitre from its great proportion of oxygen, and from the facility with which it yields it, is the basis of most detonating compositions.
EMILY.
But what is the cause of the violent detonation of gunpowder when set fire to?
MRS. B.
Detonation may proceed from two causes; the sudden formation or destruction of an elastic fluid. In the first case, when either a solid or liquid is instantaneously converted into an elastic fluid, the prodigious and sudden expansion of the body strikes the air with great violence, and this concussion produces the sound called detonation.
CAROLINE.
That I comprehend very well; but how can a similar effect be produced by the destruction of a gas?