vering the readiest method of obtaining the several principles,
either from their grand sources, air and water, or from the
decomposition of organised bodies; and in appropriating them in the best
manner to the purposes of vegetation.

EMILY.

But, among the sources of nutritive principles, I am surprised that you
do not mention the earth itself, as it contains abundance of coals,
which are chiefly composed of carbon.

MRS. B.

Though coals abound in carbon, they cannot, on account of their hardness
and impermeable texture, be immediately subservient to the purposes of
vegetation.

EMILY.

No; but by their combustion carbonic acid is produced; and this entering
into various combinations on the surface of the earth, may, perhaps,
assist in promoting vegetation.

MRS. B.

Probably it may in some degree; but at any rate the quantity of
nourishment which vegetables may derive from that source can be but very
trifling, and must entirely depend on local circumstances.

CAROLINE.

Perhaps the smoky atmosphere of London is the cause of vegetation being
so forward and so rich in its vicinity?

MRS. B.

I rather believe that this circumstance proceeds from the very ample
supply of manure, assisted, perhaps, by the warmth and shelter which the
town affords. Far from attributing any good to the smoky atmosphere of
London, I confess I like to anticipate the time when we shall have made
such progress in the art of managing combustion, that every particle of
carbon will be consumed, and the smoke destroyed at the moment of its
production. We may then expect to have the satisfaction of seeing the
atmosphere of London as clear as that of the country. --But to return to
our subject: I hope that you are now convinced that we shall not easily
experience a deficiency of nutritive elements to fertilise the earth,
and that, provided we are but industrious in applying them to the best
advantage by improving the art of agriculture, no limits can be assigned
to the fruits that we may expect to reap from our labours.

CAROLINE.

Yes; I am perfectly satisfied in that respect, and I can assure you that
I feel already much more interested in the progress and improvement of
agriculture.

EMILY.

I have frequently thought that the culture of the land was not
considered as a concern of sufficient importance. Manufactures always
take the lead; and health and innocence are frequently sacrificed to the
prospect of a more profitable