This fact appears of itself sufficient to show that the production of the asteroids must have been a subsequent event to the formation of the solar system. With respect to the asteroids, it is conceivable that the destruction of the planet which formed them may have been produced by a large meteoric visitant, with a high velocity. This hypothesis shows that such bodies may exist in considerable numbers. Such a mass might conceivably bury itself in another body, and when its motion of mass was stopped, its heat might be sufficient to produce a pressure of many thousand atmospheres. Such an explosion of developed gas might reasonably be expected to blow the body to pieces. It is generally considered that if the asteroids had been produced by the destruction of a planet, the fragments would have the same mean distance from the sun, and would pass the same points in their orbits where the destruction occurred; which is contrary to the observed motions of these bodies. The hypothesis that they are pieces of a planet is therefore not generally accepted; but these assumptions are only true if the velocity remain the same, the eccentricity of the orbit the same, and there is no resisting atmosphere. The first of these assumptions is
clearly not admissible in such a case as I have suggested, and the relative positions of the planets would influence the second. Or if this be considered to be insufficient, it is only necessary to assume that the destruction took place before the whole of the gas had been absorbed by the sun. Altogether, I think from the great eccentricity of the orbits of these bodies, from their positions, from the varying inclinations of the planes of their several ecliptics, from their varying intensity, and their small size, the only conceivable explanation of their formation is by a violent explosion. This would account for all their peculiarities. I am unacquainted with any force in nature that could produce such an explosion except the one here suggested.