tween the mental conception and the material impress. We may accurately describe the mechanical; process by which the figure on a medal is struck from a die; but trace the process as minutely as we may, we never can eliminate the mental conception of which the figure on the medal is a material embodiment.
No astronomical speculation, in modern times, has given rise to greater controversy than that known by the name of the "nebular hypothesis." Considered in its purely scientific aspect, it possesses great interest, but its peculiar claim lies in its religious bearings. To understand these, it will be necessary shortly to advert to its physical character.
A slight glance at the motions and relations of the bodies of the planetary system, at once reveals a striking amount of uniformity, not all accounted for by the principle of gravitation, or by any known cause. For example, there is no reason, that we know of, why all the planets should revolve round the sun, and rotate on their axes, in the same direction. Laplace devised his nebular hypothesis for the purpose of grouping all such uniformities under one cause or law. The following are the phenomena which he attempts thus to account for: first, the motion of the planets in the same direction, and very nearly in the same plane; secondly, the motion of the satellites in the same direction, and very nearly in the same plane with the primaries; thirdly, the motion of rotation of
