1. Of all the theories touching the origin of being, that which has received the most credit in recent days is that of Buffon, perhaps by reason of the place its author held in the scientific world, perhaps because knowledge on the subject was slender at the time.
By seeing all the planets moving in the same direction and in the same plane from the occident to the orient, from west to east, going over orbits of which the inclination does not exceed seven and a half degrees, Buffon concluded, by this uniformity, that they must all move in obedience to the same cause.
According to him, the sun being an incandescent melted mass, he supposed that a comet, having been hurled obliquely against it, by knocking against its surface, had detached a portion, which, projected into space by the violence of the shock, became divided into many fragments. These fragments have formed planets, which have continued to move circularly, by the combination of centripetal and centrifugal force, in the way communicated by the direction of the original shock; i.e., in the plane of the ecliptic.
Planets must then be parts of the incandescent substance of the sun, and consequently incandescent themselves at their commencement. They have been submitted to a cooling and consolidating process during a period of time proportionate to their volume; and, when the temperature has permitted, life has appeared on their surface.
In consequence of the gradual lowering of the central heat, the Earth would arise in a given time to a completely cool state; the liquid mass would be entirely frozen; and the air, more and more condensed, would finally disappear. The lowering of the temperature, rendering life impossible, would lead to the diminution, then to the disappearance, of all organized beings. The cooling process which has commenced at the poles would pass successively from one country to another until it reached the equator.
Such is, according to Buffon, the present state of the moon, which, smaller than the Earth, should be now an extinguished world, whence life is henceforth excluded. The sun itself will some day end in the same manner. According to his calculation, it must have taken the Earth about seventy-four thousand years to arrive at its present temperature, and in ninety-three thousand years it must see the end of organized nature.