ystem of animals
which have contributed so materially to the formation of our land. These
animals are necessarily maintained by the vegetable provision, which
is returned in the rivers to the sea, and which the land alone or
principally produces. Thus we may perceive the mutual dependence upon
each other of those two habitable worlds,--the fluid ocean and the
fertile earth.

The land is formed in the sea, and in great part by inhabitants of that
fluid world. But those animals, which form with their _exuviae_ such a
portion of the land, are maintained, like those upon the surface of
the earth, by the produce of that land to which they formerly had
contributed. Thus the vegetable matter, which is produced upon the
surface of the earth in such abundance for the use of animals, and
which, in such various shapes, is carried by the rivers into the sea,
there sustains that living system which is daily employed to make
materials for a future land.

Here is a compound system of things, forming together one whole living
world; a world maintaining an almost endless diversity of plants and
animals, by the disposition of its various parrs, and by the circulation
of its different kinds of matter. Now, we are to examine into the
necessary consequence of this disposition of things, where the matter of
this active world is perpetually moved, in that salutary circulation
by which provision is so wisely made for the growth and prosperity of
plants, and for the life and comfort of its various animals.

If, in examining this subject, we shall find that there is nothing in
the system but what is necessary, that is, nothing in the means employed
but what the importance of the end requires; if we shall find that the
end is steadily pursued, and that there is no deficiency in the means
which are employed; and if it shall be acknowledged that the end
which is attained is not idle or insignificant, we then may draw this
conclusion, That such a system is in perfect wisdom; and therefore that
this system, so far as it is found corresponding properly with
natural appearances, is the system of nature, and not the creature of
imagination.

Let us then take a cursory view of this system of things, upon which we
have proceeded in our theory, and upon which the constitution of this
world seems to depend.

Our solid earth is every where wasted, where exposed to the day. The
summits of the mountains are necessarily degraded. The solid and weighty
ma