y taken fire, and yet I did not let it touch the coals,
but I held it so very close that I suppose it caught fire merely from
the intensity of the heat.

MRS. B.

Or you might say, in other words, that the caloric which the wood
imbibed, so much elevated its temperature, and exalted its electric
energy, as to enable it to attract oxygen very rapidly from the
atmosphere.

EMILY.

Does the wood absorb oxygen while it is burning?

MRS. B.

Yes, and the heat and light are produced by the union of the two
electricities which are set at liberty, in consequence of the oxygen
combining with the wood.

CAROLINE.

You astonish me! the heat of a burning body proceeds then as much from
the atmosphere as from the body itself?

MRS. B.

It was supposed that the caloric, given out during combustion, proceeded
entirely, or nearly so, from the decomposition of the oxygen gas; but,
according to Sir H. Davy's new view of the subject, both the oxygen gas,
and the combustible body, concur in supplying the heat and light, by the
union of their opposite electricities.

EMILY.

I have not yet met with any thing in chemistry that has surprised or
delighted me so much as this explanation of combustion. I was at first
wondering what connection there could be between the affinity of a body
for oxygen and its combustibility; but I think I understand it now
perfectly.

MRS. B.

Combustion then, you see, is nothing more than the rapid combination of
a body with oxygen, attended by the disengagement of light and heat.

EMILY.

But are there no combustible bodies whose attraction for oxygen is so
strong, that they will combine with it, without the application of heat?

CAROLINE.

That cannot be; otherwise we should see bodies burning spontaneously.

MRS. B.

But there are some instances of this kind, such as phosphorus,
potassium, and some compound bodies, which I shall hereafter make you
acquainted with. These bodies, however, are prepared by art, for in
general, all the combustions that could occur spontaneously, at the
temperature of the atmosphere, have already taken place; therefore new
combustions cannot happen without the temperature of the body being
raised. Some bodies, however, will burn at a much lower temperature than
others.

CAROLINE.

But the common way of burning a body is not merely to approach it to one
already on fire, but rather to put the one in actual contact with the
other, as when I burn this pi