Page:Popular Science Monthly Volume 4.djvu/449

Rh the special materials required for it, new materials, whose dissociation point had a lower temperature, and which had consequently been prevented from combining previously, would commence upon a similar process of combustion. And so we may suppose combination to follow combination, until, finally, perhaps at a time when the planets, freighted with their living inhabitants, have begun to arrive at the sun's surface, long after the fires of the last combustion have expired, it has itself become a habitable globe, lighted and heated or served by other molecular forces from distant orbs where new conditions cause new chemical combinations, and conversions of newly-developed potential energies.

Finally, giving play to the imagination, may we not suppose further, that, in a universe extended throughout infinite space, processes of concentration similar to those supposed in the nebular hypothesis and supplemented by processes like those here indicated will go on forever, evolving worlds of continually-increasing magnificence, perhaps inhabited by living occupants of inconceivably transcendent and ever-expanding faculties?



HE planet Jupiter has passed during the last year through a singular process of change. The planet has not, indeed, assumed a new appearance, but has gradually resumed its normal aspect after three or four years, during which the mid zone of Jupiter has been aglow with a peculiar ruddy light. The zone is now of a creamy-white color, its ordinary hue. We have, in fact, reached the close of a period of disturbance, and have received a definite answer to questions which had arisen as to the reality of the change described by observers. Many astronomers of repute were disposed to believe that the peculiarities recently observed were merely due to the instruments with which the planet has been observed—not, indeed, to any fault in those instruments, but, in fact, to their good qualities in showing color. A considerable number of the earlier accounts of Jupiter's change of aspect came from observers who used the comparatively modern form of telescope known as the silvered-glass reflectors, and it is well known that these instruments are particularly well suited for the study of color-changes. Nevertheless, observations made with the ordinary refracting telescope were not wanting; and it had begun to be recognized that Jupiter really had altered remarkably in appearance, even before that gradual process of change which, by restoring his usual aspect, enabled every telescopist to assure himself that there had been no illusion in the earlier observations.