science the domain of wide generalisations. And in a few years they proved to evidence the unity of the whole inorganic world, including the most distant stars—that is, the most distant suns surrounded by their planets.
Henceforth it became impossible to speak any longer of those mysterious "fluids"—caloric, electric, magnetic—to which physicists had previously resorted for explaining the different physical forces. Now, it was proved to evidence that all the physical phenomena, including light, heat, electricity, and magnetism, are the results of those same mechanical vibrations of the molecules which produce the waves of the sea and the vibrations of a bell or a tuning-fork.
At the same time we learned the means of measuring these invisible vibratory movements of the molecules—to weigh, so to say, their energy—just as we measure the energy of movement of a stone that falls from a certain height, or of a railway train in motion.
It was demonstrated, moreover, always during those memorable years, that the celestial bodies furthest removed from us—even the myriads of suns which we see in the Milky Way—are composed of those same simple bodies, or elements, of which all other bodies on the Earth are composed, and that absolutely the same vibrations of molecules are going on there, with the same physical and chemical results, as on our planet. The movements themselves of the massive celestial bodies which travel through space according to the laws of universal gravitation, are in all probability but the resultant of all these vibrations that are transmitted in all directions for billions and trillions of miles, through the interstellar space of the Universe.
These same caloric and electric vibrations suffice to explain all chemical phenomena. Chemistry is but another chapter of molecular mechanics. And even plant and animal life in its countless manifestations is but an exchange of molecules (or rather atoms in the molecules) in that vast series of unstable, easily decomposed chemical bodies of which the living tissues of all animated beings are built up. Life is but a series of chemical decompositions and recompositions in very complex molecules: a series of fermentations due to chemical, inorganic ferments.
Moreover, during those same years it was discovered (to be proved more fully later on, in 1890–1900) that the life-processes in the living cells of the nervous system also consist of chemical
