IN CRYSTALLIZATION.

Since the discovery of the multiplying galvanometer, we know for an
absolute certainty that in every chemical action there is a production
of electricity in a more or less notable quantity, according to the
nature of the bodies in presence. Though, in the play of _affinity_,
there is a manifestation of electricity, is it the same with
_cohesion_, which also is a chemical force?

We know, on another hand, that, on causing electricity to intervene,
we bring about the crystallization of a large number of substances.
But is the converse true? Is spontaneous crystallization accompanied
with an appreciable manifestation of electricity? If we consult the
annals of science and works treating on electricity in regard to this
subject, we find very few examples and experiments proper to elucidate
the question.

Mr. Mascart is content to say: "Some experiments seem to indicate that
the solidification of a body produces electricity." Mr. Becquerel does
more than doubt--he denies: "As regards the disengagement of
electricity in the changing of the state of bodies, we find none."
This assertion is too sweeping, for further along we shall cite facts
that prove, on the contrary, that in the phenomena of crystallization
(to speak of this change of state only) there is an unequivocal
production of electricity. Let us remark, in the first place, that
when a number of phenomena of physical and chemical order
incontestably testify to the very intimate correlation that exists
between the molecular motions of bodies and their electrical state, it
would not be very logical to grant that electricity is absent in
crystallization.

Thus, to select an example from among physical effects, the vibratory
phenomena that occur in telephone transmissions, under the influence
of a very feeble electric current, show us that the molecular
constitution of a solid body is extremely variable, although within
slight limits. The feeblest modification in the electric current may
be shown by molecular motions capable of propagating themselves to
considerable distances in the conducting wire. Conversely, it is
logical to suppose that a modification in the molecular state of a
body must bring electricity into play. If, in the phenomena of
solidification, and particularly of crystallization, we collect but
small quantities of electricity, that may be due to the fact that,
under the experimental conditions involved, the electricity is more