t have almost
entirely eluded the researches of philosophers; nor do I imagine that
human art will ever be capable of investigating them with complete
success.

EMILY.

But diamond, since it consists of one simple unorganised substance,
might be, one would think, perfectly imitable by art?

MRS. B.

It is sometimes as much beyond our power to obtain a simple body in a
state of perfect purity, as it is to imitate a complicated combination;
for the operations by which nature separates bodies are frequently as
inimitable as those which she uses for their combination. This is the
case with carbon; all the efforts of chemists to separate it entirely
from other substances have been fruitless, and in the purest state in
which it can be obtained by art, it still retains a portion of hydrogen,
and probably of some other foreign ingredients. We are ignorant of the
means which nature employs to crystallize it. It may probably be the
work of ages, to purify, arrange, and unite the particles of carbon in
the form of diamond. Here is some charcoal in the purest state we can
procure it: you see that it is a very black, brittle, light, porous
substance, entirely destitute of either taste or smell. Heat, without
air, produces no alteration in it, as it is not volatile; but, on the
contrary, it invariably remains at the bottom of the vessel after all
the other parts of the vegetable are evaporated.

EMILY.

Yet carbon is, no doubt, combustible, since you say that charcoal would
absorb oxygen if air were admitted during its preparation?

CAROLINE.

Unquestionably. Besides, you know, Emily, how much it is used in
cooking. But pray what is the reason that charcoal burns without smoke,
whilst a wood fire smokes so much?

MRS. B.

Because, in the conversion of wood into charcoal, the volatile particles
of the former have been evaporated.

CAROLINE.

Yet I have frequently seen charcoal burn with flame; therefore it must,
in that case, contain some hydrogen.

MRS. B.

Very true; but you must recollect that charcoal, especially that which
is used for common purposes, is not perfectly pure. It generally retains
some remains of the various other component parts of vegetables, and
hydrogen particularly, which accounts for the flame in question.

CAROLINE.

But what becomes of the carbon itself during its combustion?

MRS. B.

It gradually combines with the oxygen of the atmosphere, in the same way
as sulphur and phosphoru