Page:Popular Science Monthly Volume 71.djvu/276

270 let us suppose to be radiated spherically—in all directions—to immeasurable but still definite distances in the previously vacant space—a certain inexpressibly great yet limited number of unimaginably yet not infinitely minute atoms." Differences of size and form taken conjointly cause differences of kind among these atoms.

The natural tendency of these subdivisions of matter is towards the unity whence they sprang. On the fulfilment of the radiation, the diffusive energy being withdrawn, to avert this tendency, and the consequent absolute coalition of the atoms, repulsion makes its appearance. These two principles, attraction and repulsion, being the "sole properties through which we perceive the universe," "we are fully justified in assuming that matter exists only as attraction and repulsion—that attraction and repulsion are matter, there being no conceivable case in which we may not employ the term "Matter," and the terms "Attraction" and "Repulsion," taken together, as equivalent, and therefore convertible, expressions in logic." The nature of repulsion Poe refuses to attempt to determine, but he states it to be identical with electricity. To it we should probably refer the various physical appearances of light, heat and magnetism, and still more so the phenomena of vitality, consciousness and thought. Attraction is the material, repulsion the spiritual principle of the universe. As Poe declares that both together constitute matter, he thus states a sort of crude monism.

Since the diffused matter was radiated in a generally equable manner, we may conceive it as arranged in concentric spherical strata about its origin. This at once leads us to the explanation of the mode in which attraction acts—the reason, that is, why gravitation varies inversely as the square of the distance between the attracting masses. For, since the surfaces of spheres vary as the square of their radii, the number of atoms in each concentric spherical stratum is proportional to the square of that stratum's distance from the center. But as the number of atoms in any stratum is the measure of the force that emitted that stratum, that force itself is directly proportional to the square of its stratum's distance from the center. Now, on the fulfilment of the diffusion, the modus operandi of the attractive force is, of course, the converse of that of the diffusive; in other words, each particle of matter seeks its original condition of unity by attracting its fellow-atoms with a force inversely proportional to the square of the distances between them.