very greatly extended. Hence, considering the extreme slowness of the process, it may be reasonable to conclude that the forms ultimately developed would be identical with those which would be assumed by liquid masses having the same relative positions and velocities.
The determination of these forms is a problem for the mathematicians. In the absence of analysis, no reason is manifest for supposing that the forms of equilibrium would be materially different just before and just after contact. May it not be that the order of change would be a partial reversal of certain supposed processes of the nebular hypothesis? Thus the moon may be gradually elongated into a closed ring which will slowly contract upon the earth as the energy of angular velocity is gradually dissipated by the friction of the medium. In any event there seems to be no good reason to suppose that there will be such a sudden leap in the final osculation or embrace as would result in a catastrophe.
The same considerations apply to the gravitational relations between planets and suns. Other very important relations between these bodies, however, with which organic life is more especially concerned, require attention. One fundamental requisite to all known terrestrial organic life is the conversion, within living bodies, of molecular energy, either into molar motions, or into potential energy which may afterward be thus converted. All living animals and plants, therefore, depend for their existence upon the passage through their bodies, in the movement toward distribution and equalization, of heat, light, and other molecular forces originating in the sun.
The integrity of cosmical evolution in relation to organic life, accordingly, seems to require the maintenance of great central laboratories where molecular disturbances of sufficient intensity and quantity can be continually generated, and their effects distributed throughout the universe. Notwithstanding the enormous expenditure of heat by the sun, its temperature is supposed to have been maintained about the same as at present for a very long period of time in the past, and no reason is manifest why this fixed temperature will not continue for a very long time in the future. Doubtless, operations are going on in the sun which it would be impossible to imitate in terrestrial laboratories. May it not be that the conditions of materials and the circumstances of pressure, chemical affinity, etc., are such, that substances more elementary than our so-called chemical elements are uniting with an energy far exceeding that of any chemical combination we can effect, and so prodigious as to maintain, at comparatively small expenditure of material, the sun's temperature at that enormous degree which marks the dissociation point of the tremendously energetic combination? The duration of the combination or combustion would thus be prolonged to an enormously remote period. At last, when all the potential energy due to this particular reaction became exhausted by the combination of all