space, which is probably flat, but which possibly may turn out to be inherently crooked. And now, when somebody shakes his head and proposes to examine whether there is not something wrong with this whole mode of philosophizing, which mistakes crutches for limbs, and scaffolds for buildings, Professor Newcomb hurls a wooden thunder-bolt at him, or a reviewer in the New York "Critic" reminds him that "the sound thinker gives himself little uneasiness respecting the laws of thought."
Now let us look for a moment at the atom. The physicist or chemist gets it originally as an ancient heir-loom, handed down from the times of Democritus or Lucretius. It is a solid body, with attachments of hooks and loops. The modern scientist takes off the attachments, and holds on to the main solid body, polishing it for his use. So this body becomes round; but in course of time appear the mineralogist and chemist with their morphological laws, such as the law of Mitscherlich, with theories of polarity or valency, or what not; and to accommodate them it is proclaimed that the atom is a cube or a rhomb or an octahedron, or whatever else will silence the most clamor. After a while, Kroenig or Clausius declares that, in the interest of his kinetic theory of gases, he must insist on the perfect sphericity of the atoms or ultimate molecules; and thenceforward (for a month at least) they are spherical. But, at the expiration of the month, Maxwell points to certain anomalous facts which are supposed to be inconsistent with atomic sphericity, and he suggests that it be modified so as to give the atoms the form of oblate or prolate spheroids; and, of course, his suggestion is adopted. In a short time some physicist rushes out of his laboratory or study, and announces that he has just obtained experimental results or arrived at theoretical conclusions requiring an utter rejection, not only of the definite figure of the atom, but of its entire bulk; and forthwith it is subtilized into a mere center of force. But now the physicist is reminded that force must have a substratum, and that its indispensable correlate is inertia. At this juncture the pangeometer flits upon the scene, and offers the perplexed physicist his fourth dimension in which to lodge both the extension and "intension"—i. e.,—mass of the centers of force, assuring him that he may have the mere punctuality of the atom in ordinary space, and behind it, in space of four dimensions, any amount of bulk and weight. At this stage of the proceedings the physicist begins to look desperate; perhaps he is silently meditating the question, What is to become of experimental research if the properties of things can vanish ad libitum, and retire into the recesses of the pangeometrical regions? And yet, woe to him who ventures to suggest to the chemist that the origin of the trouble is not in his retorts, but in the sincipital alembic through which all his results are at last distilled, or to show the physicist that there is no defect in the lenses of his microscope, but great want of achromatism in those of his intellect! He speedily learns that the
