We have thus surveyed the machine in general, with those moving powers,
by which its operations, diversified almost _ad infinitum_, are
performed. Let us now confine our view, more particularly, to that part
of the machine on which we dwell, that so we may consider the natural
consequences of those operations which, being within our view, we are
better qualified to examine.

This subject is important to the human race, to the possessor of this
world, to the intelligent being Man, who foresees events to come, and
who, in contemplating his future interest, is led to inquire concerning
causes, in order that he may judge of events which otherwise he could
not know.

If, in pursuing this object, we employ our skill in research, not in
forming vain conjectures; and if _data_ are to be found, on which
Science may form just conclusions, we should not long remain in
ignorance with respect to the natural history of this earth, a subject
on which hitherto opinion only, and not evidence, has decided: For in no
subject, perhaps, is there naturally less defect of evidence, although
philosophers, led by prejudice, or misguided by false theory, may have
neglected to employ that light by which they should have seen the system
of this world.

But to proceed in pursuing a little farther our general or preparatory
ideas. A solid body of land could not have answered the purpose of a
habitable world; for, a soil is necessary to the growth of plants; and a
soil is nothing but the materials collected from the destruction of the
solid land. Therefore, the surface of this land, inhabited by man,
and covered with plants and animals, is made by nature to decay, in
dissolving from that hard and, compact state in which it is found below