So long as the atoms of matter were regarded as hard round particles, they were assumed to be inert and only active when acted upon by what were called forces, which were held to be entities of some sort, independent of matter. These could pull or push it here or there, but the matter was itself incapable of independent activity. All this is now changed, and we are called upon to consider every atom as being itself a form of energy in the same sense as heat or light are forms of energy, the energy being embodied in particular forms of motion. Light, for instance, is a wave motion of the ether. An atom is a rotary ring of ether. Stop the wave motion, and the light would be annihilated. Stop the rotation, and the atom would be annihilated for the same reason. As the ray of light is a particular embodiment of energy, and has no existence apart from it, so an atom is to be regarded as an embodiment of energy. On a previous page it is said that energy is the ability of one body to act upon and move another in some degree. An atom of any kind is not the inert thing it has been supposed to be, for it can do something. Even at absolute zero, when all its vibratory or heat energy would be absent, it would be still an elastic whirling body pulling upon every other atom in the universe with gravitational energy, twisting other atoms into conformity with its own position with its magnetic energy; and, if such ether rings are like the rings which are made in air, will not stand still in one place even if no others act upon it, but will start at once by its own inherent energy to move in a right line at right angles to its own plane and in the direction of the whirl inside the ring. Two rings of wood or iron might remain in contact with each other for an indefinite time, but vortex-rings will not, but will beat each other away as two spinning tops will do if they touch ever so gently. If they do not thus separate it is because there are other forms of energy acting to press them together, but such external pressure will be lessened by the rings' own reactions. It is true that in a frictionless medium like the ether one cannot at present see how such vortex-rings could be produced in it. Certainly not by any such mechanical methods as are employed to make smoke-rings in air, for the friction of the air is the condition for producing them. However they came to be, there is implied the previous existence of the ether and of energy in some form capable of acting upon it in a manner radically different from any known in physical science.