rs to explain the appearance here
examined by the constant though imperceptible operation of springs.
The present purpose is not so much concerning the explanation of those
appearances, as to inquire if these be the general appearances of things
over all the surface of the earth.

The general appearance here is that of land washed away upon the surface
by water, which has every where left the marks of its operation in
the shape of the ground. As for any particulars in the shape of this
water-worn surface, this can only be explained in knowing the nature
of the soil and solid parts, and the circumstances of the operation in
which they have been wasted.

If the shape of the land here described by Mr Marsden has been produced
by means of water, it must be by water moving from a higher to a lower
place; and, in that respect, it is the same operation which every where
prevails, in producing similar effects, although it is not every where
that this effect comes to be the object of our notice. It is therefore
so necessary to illustrate, in giving a diversity of cases. But it is
not every case that can be understood as belonging to this rule; for,
though the shape of every part has been modified by the operation of
this cause, it is not every where that this relation of cause and effect
is immediately perceived. There must be a certain regularity in the
parts to be described, and a certain conformity wish those in which we
have no doubt, or in which we certainly acknowledge the efficacy of the
cause.

In America, this system of swamps and savannas are to be found upon a
large scale; but for this very reason, they are not so remarkable to
men. Man only sees a system of things, so far as that system is more
immediately within the reach of his perception; for, without having
prepared _media_, by which he may compare things that are distant either
in their nature or their place, How could he judge those things to be
connected in a system? It is in this manner that, seeing only the small
part of an extended system of things, he sees no system in it, and,
consequently he cannot give any scientifical description of the subject.

There is another case in which men of science, or systematising men,
are apt to fall into delusion: it is not from any deficiency of seeing
effects, and knowing general causes; it is from the misapplication
of known causes to effects which are perceived. We have a remarkable
example of this in the view whi