More exact knowledge being now had of the relations existing among the different so-called elements, it has become possible to work out the atomic theory, so far as to prove that the law of chemical attraction is identical with that of gravitation; namely, that its force is directly in proportion to the number and mass of the atoms, and inversely as the squares of their distances: _atomic distances_ being, by extremely abstruse calculations, approximately estimated. The long wished for full explanation of the relations between frictional electricity, voltaism, magnetism, heat, and light, seems likely soon to be obtained; and, consequently, also the exact physical relations of the vital or formative force of animals and plants. It is quite well understood that, as Newton himself anticipated, the law of gravitation was but a step, though a very great and important one, in the generalization of cosmic changes and forces. We seem to be on the eve of another advance, needing only the completion of some difficult mathematical and physical analyses,--in which all so-called attractions and repulsions whatever will be resolved into results or phenomena of motion; ethereal, atomic, molecular, and massive motions; whose mutual reactions and momenta make the infinite complexity of the universe. Towards such a conclusion, serviceable contributions were made many years since, by three American cosmologists, Norton, Pliny Chase, and Kirkwood. The 320th asteroid was discovered at Pike's Peak observatory, during last summer. I may jot down here too, the record of the first observation of a new telescopic comet, last month, by a senior student of Bryn Mawr College for Women. Australia, according to the address mentioned, has at last furnished to palæontologists the real _missing link_, not between men and apes, which they have generally given up, but between vertebrate and invertebrate animals. So that the famous ascidian mollusc, with a semi-vertebral larval stage, which nourished in the writings of Darwin and others, is no longer needful. The fossil referred to is an ancient fish-like worm, or worm-like fish, to which the name of Entomicthys amphisoma has been provisionally given. It is still more remarkable than the amphioxus or lancelet, which has been long known. By the improved methods of measuring both space and time in practical astronomy, it has been rendered nearly or quite certain that our earth is gradually approaching the sun; and that the same is true of all the other planets. Small as the rate of this approach is, it is enough to confirm the belief of Sir William Thomson and others in the 19th century, that our solar system is constructed for finite (not, as Laplace and Lagrange thought, infinite) duration; the whole economy of planets will at last run down like a clock, and all the elements will be melted together with fervent heat.