in which we may look for the transactions of time
past, in the present state of things, upon the surface of this earth,
and read the operations of an ancient date in those which are daily
transacted under our eye. The one of these is to examine the soil, and
to trace the origin of that which we find loose upon the surface of the
earth, or only compacted by the soft and cohesive nature of some of its
materials. In thus studying the soil we shall learn the destruction of
the solid parts; and though, by this means, we cannot form an estimate
of the quantity of this destruction which had been made, we shall, upon
many occasions, see a certain _minimum_ of this quantity which may
perhaps astonish us.

The second method here proposed, is to examine the solid part of the
earth, in order to learn the quantity of matter which had been separated
from this mass. Here also we shall not be able to compute the quantity
of what had been destroyed; but we shall every where find a certain
_minimum_ of this quantity, which will give us an extensive view with
regard to the operation of the elements and seasons upon the surface of
this earth. We shall now examine more particularly those two ways of
judging with regard to the operations of time past, and the changes
which have been made upon the surface of our land, by those active
causes, which, being in the constitution of this earth, must continue to
operate with undiminished power, and tend to preserve the _whole_ amidst
the destruction of its particular parts.

The quality of the soil or travelled earth of the globe is various;
because the solid parts, from the destruction of which the soil is
formed, consist of very different substances, in the different portions
of each country. Thus, in one part of a country, the soil will be
calcareous, or containing much of that species of substance; in another,
again, it will be argillaceous; in another sandy, where the prevailing
substance is siliceous. These are the original soils; other substances
may be considered as adventitious to this soil, though natural to the
surface of the earth, which is covered with plants and animals. The
substance of those animal and vegetable bodies, mixed with the soil,
adds greater fertility to the earth, and gives a soil which is still
more compounded in its nature, but still composed of those materials now
enumerated.

We have been now supposing the solid parts below, or in the same field,
as furnishing ma