y within and into
inanimate material systems. It is not assumed here that these
phenomena are restricted in their sphere of action to inanimate
nature. It is, in fact, very certain that they are not; but while
they confer on dead nature its own dynamic tendencies, it will
appear that their effects are by various means evaded in living
nature. We, therefore, treat of them as characteristic of
inanimate actions. We accept as fundamental to all the
considerations which follow the truth of the principle of the
Conservation of Energy.[1]

[1] "The principle of the Conservation of Energy has acquired so
much scientific weight during the last twenty years that no
physiologist would feel any confidence in an experiment which
showed a considerable difference between the work done by the
animal and the balance of the account of Energy received and
spent."--Clerk Maxwell, _Nature_, vol. xix., p. 142. See also
Helmholtz _On the Conservation of Force._

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Whatever speculations may be made as to the course of events very
distant from us in space, it appears certain that dissipation of
energy is at present actively progressing throughout our sphere
of observation in inanimate nature. It follows, in fact, from the
second law of thermodynamics, that whenever work is derived from
heat, a certain quantity of heat falls in potential without doing
work or, in short, is dissipated. On the other hand, work may be
entirely converted into heat. The result is the heat-tendency of
the universe. Heat, being an undirected form of energy, seeks, as
it were, its own level, so that the result of this heat-tendency
is continual approach to uniformity of potential.

The heat-tendency of the universe is also revealed in the
far-reaching "law of maximum work," which defines that chemical
change, accomplished without the intervention of external energy,
tends to the production of the body, or system of bodies, which
disengage the greatest quantity of heat.[1] And, again, vast
numbers of actions going on throughout nature are attended by
dissipatory thermal effects, as those arising from the motions of
proximate molecules (friction, viscosity), and from the fall of
electrical potential.

Thus, on all sides, the energy which was once most probably
existent in the form of gravitational potential, is being
dissipated into unavailable forms. We must

[1] Berthelot, _Essai de Mecanique Chimique._

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recognize dissipation as an inevitable attend