_Mr. Charles Morris on the pre-nebular condition of matter._—Others again suppose matter to be present everywhere throughout space. This view has been ingeniously advocated by Mr. Charles Morris in an article on “The Matter of Space,” which appeared in _Nature_, February 8, 1883. The hypothesis of an ether specially distinct from matter he considers to be a gratuitous assumption, and one of the last surviving relics of eighteenth century science, and, unless it can be proved that highly disintegrated matter is positively incapable of conveying light vibrations, there is no warrant for assigning this duty to a distinct form of substance. But that matter exists in outer space in the same conditions as in planetary atmospheres he thinks is improbable. Its duty as a conveyer of radiant vibrations seems to require a far greater tensity, and its disintegration is probably extreme. Assuming matter throughout the universe—here as condensed spheres, and there in outer space as highly rarified substance—the atmospheric envelopes of the spheres, he considers, will gradually shade off into the excessively rare matter of mid-space. Matter may exist in countless conditions as to simplicity and complexity, &c., but the base particle he assumes to be the same under all conditions. In the spheres there is matter ranging from the simplest elementary gases, through the mineral compounds of the solid surface, to the highly compounded organic molecules. In outer space the variation is in the opposite direction; the matter existing there in a highly disintegrated condition. Every particle he considers to possess a certain amount of motor energy in the form of heat. As the total amount of this energy in the universe remains unchanged, a particle can only lose energy by transferring it to others. This heat energy acts, of course, in opposition to gravity: it tends to repel the particles from each other, while gravity, on the other hand, tends to draw them together. The former acts as a centrifugal, the latter as a centripetal energy. If the heat momentum of the particles be insufficient to constitute a centrifugal energy equal to the centripetal energy of gravitation, then the material contents of space will be drawn into the attracting spheres as atmospheric substance, and outer space, in this case, will be left destitute of matter. If, on the contrary, the centrifugal energy of the particles be sufficient to resist gravitation, then the particles will remain free, and space will continue to be occupied with matter. As has been stated, the sum of motor energy in the universe remaining unchanged, the aggregation of atmospheric substance around any planet resulting from the loss of motor energy must cause an increase of motor energy in the particles outside.