Page:Popular Science Monthly Volume 10.djvu/725

Rh were at any time stopped, it would be resolved into just the amount of heat necessary to expand the mass again to its original dimensions.

The attractive forces, gravity, chemical affinity, and cohesion, whether these forces are many or one, are inherent properties of matter. Every atom has its definite capacity of attraction, which may be exercised or not according to circumstances. For it is evident that an attracting body may be at the same time drawing toward itself a million other like bodies, or none at all, without change of its power of attraction. In like manner the magnet has a definite lifting power whether it is actually holding up a weight or not. If this attribute of matter is not operative, or but partially so, it is because heat, or motion, or some repellent force, is holding the atoms or the masses at a distance from each other, and thus opposing the exercise of it. The sum, however, of the attracting power belonging to the world of matter is as fixed as the quantity of matter itself. And I think it is in the highest degree probable that there is in the universe precisely enough repulsive force or heat to overcome all this inherent power of attraction. When all motion of the masses and of the atoms is resolved into repulsive energy, and brought to bear on the elements of matter, I imagine that they must completely fill the bounds or the infinity of space. Then, if there were perfect equilibrium or rest, no further changes or effects could ever be manifested. Such a condition, however, could probably never result from natural causes, for the time necessary to the perfect balance of the forces must be as infinite as the space through which they extend, and to "set bounds to space" has puzzled philosophy from a very ancient date. If, on the other hand, the universe of matter was created in a state of absolute rest, we have the further and necessary provision that the Spirit of God moved on the face of his creation, and thus unbalanced the forces. But the equilibrium once broken, in whatever manner, from that moment evolution must inevitably proceed. For, let there be an overbalancing of the aggregating force in ever so little or much, an equivalent of the opposing force must thereafter find some other work to do, and the field is effectually given up to the mighty agency that combines, and constructs, and brings order out of chaos.

So long and in proportion as the forming worlds continue to contract their dimensions, the rotations and revolutions increase in their velocity. Thus in the rapid and ever-speeding movements of the heavenly bodies there is stored up the ever-increasing reserve of heat that is liberated from the great contest with gravity. But in the progress of concentration there comes a time when the atoms of matter have approached each other sufficiently near for other forces of attraction, equally correlative of heat, to come into play—chemical affinity between molecules of unlike nature, and cohesion between those of like kind. Under the latter term are included all the changes of state which are the result of cooling. By these attractions heat is set free