subsisting in situations where the land affords him little more than
it does the seal on which he feeds. The growth of terrestrial plants,
however, seems necessary to the idea of a habitable country; and, for
the growth of plants, there is required soil: Now, this is only to be
procured by the resolution or decay of solid land.

We are not to consider the resolution of our land as being the effect
of accident, while it is performed by the operations of the sun and
atmosphere, by the alternate action of moisture and of drought, and by
the casual operations of a river in a flood. Nothing is more steady than
the resolution of our land; nothing rests upon more certain principles;
and there is nothing which in science may be more easily investigated.

Calcareous, argillaceous, and other soluble earths, compose many of
the strata; but in many more, which are partly or chiefly composed
of insoluble substances, those soluble earths are mixed in various
proportions. Now, when the siliceous substance, which is the insoluble
part, shall be supposed resisting every effort of the elements towards
its dissolution, those compound masses upon the surface of the earth,
however endued with hardness and solidity, are gradually impaired by the
dissolution of some of their constituent parts, and by the separation of
others which are thus exposed to the ablution of water. In like manner,
by the resolution of the surrounding parts, the solid _silex_, which is
supposed to be insoluble, is removed from its bed, and thus suffers new
parts of the solid land to be exposed to those injuries of the air, by
which the general good of plants, of animals, and even of future worlds,
are consulted.

The solid land is resolved into stones, gravel, sand, earths, and clays;
all or either of these, by retaining moisture, and affording places for