Every thing in the universe is in motion: the essence of matter is to
act: if we consider its parts, attentively, we shall discover there is
not a particle that enjoys absolute repose. Those which appear to us to
be without motion, are, in fact, only in relative or apparent rest; they
experience such an imperceptible motion, and expose it so little on
their surfaces, that we cannot perceive the changes they undergo. All
that appears to us to be at rest, does not, however, remain one instant
in the same state. All beings are continually breeding, increasing,
decreasing, or dispersing, with more or less dullness or rapidity. The
insect called EPHEMERON, is produced and perishes in the same day; of
consequence, it experiences the greatest changes of its being very
rapidly, in our eyes. Those combinations which form the most solid
bodies, which appear to enjoy the most perfect repose, are nevertheless
decomposed, and dissolved in the course of time. The hardest stones, by
degrees, give way to the contact of air. A mass of iron, which time, and
the action of the atmosphere, has gnawed into rust, must have been in
motion, from the moment of its formation, in the bowels of the earth,
until the instant we behold it in this state of dissolution.

Natural philosophers, for the most part, seem not to have sufficiently
reflected on what they call the _nisus_; that is to say, the incessant
efforts one body is making on another, but which, notwithstanding
appear, to our superficial observation, to enjoy the most perfect
repose. A stone of five hundred weight seems to rest quiet on the earth,
nevertheless, it never ceases for an instant, to press with force upon
the earth, which resists or repulses it in its turn. Will the assertion
be ventured, that the stone and earth do not act? Do they wish to be
undeceived? They have nothing to do but interpose their hand betwixt the
earth and the stone; it will then be discovered, that notwithstanding
its seeming repose, the stone has power adequate to bruise it; because