[Note 4: Stalactical and certain ferruginous concretions may seem
to form an exception to the generality of this proposition. But an
objection of this kind could only arise from a partial view of things;
for the concretion here is only temporary; it is in consequence of a
solution, and it is to be followed by a dissolution, which will be
treated of in its proper place.]

Whatever conclusions, therefore, by means of this science, shall be
attained, in just reasoning from natural appearances, this must be held
as evidence, where more immediate proof cannot be obtained; and, in
a physical subject, where things actual are concerned, and not the
imaginations of the human mind, this proof will be considered as
amounting to a demonstration.


SECTION II.

An Investigation of the Natural Operations employed in consolidating
the Strata of the Globe.

We are now about to investigate those mineral operations of the globe by
which the qualities of hardness and solidity, consequently of strength
and durability, are procured to great bodies of this earth.

That those qualities are not original to such bodies, but actually
superinduced in the natural operations of the earth, will appear from
the examination of some of the hardest and most solid of those mineral
bodies. In such masses, (for example of flint and agate,) we find
included shells and coralline bodies. Consequently, there must be a