or
less completely absorbed by the work of crystal building.

On another hand, the behavior of electricity shows in advance the
multiple role that this agent may play in the various physical,
chemical, and mechanical phenomena.

There is no doubt that electricity exists immovable or in circulation
everywhere, latent or imperceptible, around us, and within ourselves,
and that it enters as a cause into the majority of the chemical,
physical, and mechanical phenomena that are constantly taking place
before our eyes. A body cannot change state, nature, temperature,
form, or place, even, without electricity being brought into play, and
without its accompanying such modifications, if it presides therein.
Like heat, it is _the_ natural agent _par excellence_; it is the
invisible and ever present force which, in the ultimate particles of
matter, causes those motions, vibrations, and rotations that have the
effect of changing the properties of bodies. Upon entering their
intimate structure, it orients or groups their atoms, and separates
their molecules or brings them together. From this, would it not be
surprising if it did not intervene in the wonderful phenomenon of
crystallization? Crystallization, in fact, depends upon _cohesion_,
and, in the thermic theory, this force is not distinct from affinity,
just as solution and dissociation are not distinct from combination.

On this occasion, it is necessary to say that, between affinity, heat,
and electricity there is such a correlation, such a dependency, that
physicists have endeavored to reduce to one single principle all the
causes that are now distinct. The mechanical theory of heat has made a
great stride in this direction.

The equivalence of the thermic, mechanical and chemical forces has
been demonstrated; the only question hereafter will be to select from
among such forces the one that must be adopted as the sole principle,
in order to account for all the phenomena that depend upon these
causes of various orders. But in the present state of science, it is
not yet possible to explain completely by heat or electricity, taken
isolatedly, all the effects dependent upon the causes just mentioned.
We must confine ourselves for the present to a study of the relations
that exist between the principal natural forces--affinity, molecular
forces, heat, electricity, and light. But from the mutual dependence
of such forces, it is admitted that, in every natural phenomenon,
ther