opinion of water in
relation to its chemical character. But there is no necessity thus to
violate our chemical principles, in order to explain certain natural
appearances; more especially if those appearances may be explained in
another manner, consistently with the known laws of nature.

If, again, it is by means of heat and fusion that the loose and porous
structure of strata shall be supposed to have been consolidated, then
every difficulty which had occurred in reasoning upon the power or
agency of water is at once removed. The loose and discontinuous body of
a stratum may be closed by means of softness and compression; the porous
structure of the materials may be consolidated, in a similar manner, by
the fusion of their substance; and foreign matter may be introduced into
the open structure of strata, in form of steam or exhalation, as well as
in the fluid state of fusion; consequently, heat is an agent competent
for the consolidation of strata, which water alone is not. If,
therefore, such an agent could be found acting in the natural place of
strata, we must pronounce it proper to bring about that end.

The examination of nature gives countenance to this supposition, so far
as strata are found consolidated by every species of substance,
and almost every possible mixture of those different substances;
consequently, however difficult it may appear to have this application
of heat, for the purpose of consolidating strata formed at the bottom of
the ocean, we cannot, from natural appearances, suppose any other cause,
as having actually produced the effects which are now examined.

This question, with regard to the means of consolidating the strata of
the globe, is, to natural history, of the greatest importance; and it is
essential in the theory now proposed to be given of the mineral system.
It would, therefore, require to be discussed with some degree of
precision in examining the particulars; but of these, there is so great
a field, and the subject is so complicated in its nature, that volumes
might be written upon particular branches only, without exhausting what
might be laid upon the subject; because the evidence, though strong in
many particulars, is chiefly to be enforced by a multitude of facts,
conspiring, in a diversity of ways, to point out one truth, and by the
impossibility of reconciling all these facts, except by means of one
supposition.

But, as it is necessary to give some proof of that which is