heat, moreover, do not permit us to see in onr present simple bodies polymers of the same substance comparable to known polymers. The specific heat of the last increases, according to Woestyn's law, with the complex structure of their molecule, while the specific heat of simple bodies varies, according to Dulong and Petit's law, inversely as their equivalents.
We may, nevertheless, conceive the unity of matter in another sense. Some chemists oppose to Prout's hypothesis a new and more comprehensive one, which consists in regarding the elements as states of stable equilibrium in which matter exhibits itself. "In this order of thought," says M. Berthelot, "a body reputed simple could be destroyed but not decomposed in the ordinary sense. At the moment of destruction it would at once transform itself into one or several other simple bodies, identical with or resembling the existing elements. But the atomic weights of the new elements could not offer any commensurable relation with the atomic weight of the primary body from which they are produced by metamorphosis. More than this: by working under different conditions we might see appear sometimes one system, sometimes another, of simple bodies, developed by the transformation of another element. Only the absolute weight would remain invariable in the course of the transmutations."
Even under this hypothesis the hope of forming simple bodies need not seem chimerical. Unfortunately, we have no more reasons for encouraging it than for condemning it. All that can be said respecting it is that the present condition of science does not allow us to discern any method that will lead to the end. Would it not be wiser, then, to make our theories more complete rather than venture into this darkness without a guiding thread? It is no mystery to any one that they greatly need improvement. The imponderable fluids have only just passed away; the ether, too, seems to be already withdrawing, taking along with it, perhaps, the atom of the chemists; and does it not seem that everything is about to be explained by motion?
M. Berthelot discusses these questions with his well-known vigor and originality. His work, erudite and pointed, is particularly instructive to the thinker. He in fact restores to our view the affiliation of the systems that were conceived at the birth of chemistry, and which have been revived at our time in the effort to resolve the eternal problem of the constitution of matter. —Translated for The Popular Science Monthly from the Revue Scientifique.