_Apparent Differences between Living and Brute Bodies. The Two Kingdoms._—It seems at first impossible that there should be any essential similarity between an inanimate object and a living being. What resemblance can be discovered between a stone, a lion, and an oak? A comparison of the inert and immovable pebble with the leaping animal, and with the plant extending its foliage gives an impression of vivid contrast. Between the organic and the inorganic worlds there seems to be an abyss. The first impressions we receive confirm this view; superficial investigation furnishes arguments for it. There is thus aroused in the mind of the child, and later in that of the man, a sharply marked distinction between the natural objects of the mineral kingdom on the one hand, and those of the two kingdoms of living beings on the other. But a more intimate knowledge daily tends to throw doubt upon the rigour or the absolute character of such a distinction. It shows that brute matter can no longer be placed on one side and living beings on the other. Scientists deliberately speak of “the life of matter,” which seems to the average man a contradiction in terms. They discover in certain classes of mineral bodies almost all the attributes of life. They find in others fainter, but still recognizable indications of an undeniable relationship. We propose to pass in review these analogies and resemblances, as has already been done in a fairly complete manner by Leo Errera, C. E. Guillaume, L. Bourdeau, Ed. Griffon, and others. We will consider the fine researches of Rauber, of Ostwald, and of Tammann upon crystals and crystalline germs—researches which are merely a continuation of those of Pasteur and of Gernez. These show that crystalline bodies are endowed with the principal attributes of living beings—_i.e._, a rigorously defined form; an aptitude for acquiring it, and for re-establishing it by repairing any mutilations that may be inflicted upon it; nutritive growth at the expense of the mother liquor which constitutes its culture medium; and, finally—a still more incredible property—all the characteristics of reproduction by generation. Other curious facts observed by skilful physicists—W. Roberts-Austen, W. Spring, Stead, Osmond, Guillemin, Charpy, C. E. Guillaume—show that the immutability even of bodies supposed to be the most rigid of all, such as glass, the metals, steel, and brass, is apparent rather than real. Beneath the surface of the metal that seems to us inert there is a swarming population of molecules, displacing each other, moving about, and arranging themselves so as to form definite figures, and assuming forms adapted to the conditions of the environment. Sometimes it is years before they arrive at the state of ultimate and final equilibrium—which is that of eternal rest.