nto centres constituted of atoms of
electricity. On the other hand, he would have found in the bursting
forth of these new doctrines one more proof in support of his idea
that science is indissolubly bound to atomism.

From the philosophical point of view, M. Hannequin, examining the
reasons which may have called these links into being, arrives at the
idea that they necessarily proceed from the constitution of our
knowledge, or, perhaps, from that of Nature itself. Moreover, this
origin, double in appearance, is single at bottom. Our minds could
not, in fact, detach and come out of themselves to grasp reality and
the absolute in Nature. According to the idea of Descartes, it is the
destiny of our minds only to take hold of and to understand that which
proceeds from them.

Thus atomism, which is, perhaps, only an appearance containing even
some contradictions, is yet a well-founded appearance, since it
conforms to the laws of our minds; and this hypothesis is, in a way,
necessary.

We may dispute the conclusions of M. Hannequin, but no one will refuse
to recognise, as he does, that atomic theories occupy a preponderating
part in the doctrines of physics; and the position which they have
thus conquered gives them, in a way, the right of saying that they
rest on a real principle. It is in order to recognise this right that
several physicists--M. Langevin, for example--ask that atoms be
promoted from the rank of hypotheses to that of principles. By this
they mean that the atomistic ideas forced upon us by an almost
obligatory induction based on very exact experiments, enable us to
co-ordinate a considerable amount of facts, to construct a very general
synthesis, and to foresee a great number of phenomena.

It is of moment, moreover, to thoroughly understand that atomism does
not necessarily set up the hypothesis of centres of attraction acting
at a distance, and it must not be confused with molecular physics,
which has, on the other hand, undergone very serious checks. The
molecular physics greatly in favour some fifty years ago leads to such
complex representations and to solutions often so undetermined, that
the most courageous are wearied with upholding it and it has fallen
into some discredit. It rested on the fundamental principles of
mechanics applied to molecular actions; and that was, no doubt, an
extension legitimate enough, since mechanics is itself only an
experimental science, and its principles, establishe