his economy,
and, without the productive power of plants, it would finally be
extinguished.[17]

[Note 17: See Dissertations on different subjects of Natural Philosophy,
part II.]

The animals of the former world must have been sustained during
indefinite successions of ages. The mean quantity of animal matter,
therefore, must have been preserved by vegetable production, and the
natural waste of inflammable substance repaired with continual addition;
that is to say, the quantity of inflammable matter necessary to the
animal consumption, must have been provided by means of vegetation.
Hence we must conclude, that there had been a world of plants, as well
as an ocean replenished with living animals.

We are now, in reasoning from principles, come to a point decisive of
the question, and which will either confirm the theory, if it be just,
or confute our reasoning, if we have erred. Let us, therefore, open
the book of Nature, and read in her records, if there had been a world
bearing plants, at the time when this present world was forming at the
bottom of the sea.

Here the cabinets of the curious are to be examined; but here some
caution is required, in order to distinguish things perfectly different,
which sometimes are confounded.

Fossil wood, to naturalists in general, is wood dug up from under
ground, without inquiring whether this had been the production of the
present earth, or that which had preceded it in the circulation of land
and water. The question is important, and the solution of it is, in
general, easy. The vegetable productions of the present earth, however
deep they may be found buried beneath its surface, and however ancient
they may appear, compared with the records of our known times, are new,
compared with the solid land on which they grew; and they are only
covered with the produce of a vegetable soil, or the alluvion of the
present land on which we dwell, and on which they had grown. But the
fossil bodies which form the present subject of inquiry, belonged to
former land, and are found only in the sea-born strata of our present
earth. It is to these alone that we appeal, in order to prove the
certainty of former events.

Mineralised wood, therefore, is the object now inquired after; that wood
which had been lodged in the bottom of the sea, and there composed part
of a stratum, which hitherto we have considered as only formed of the
materials proper to the ocean. Now, what a profusion of thi