The ordinary notion of movement is wholly confined to that which is called molar, that is, the motion of masses. Moles=a mass. Thus the movements of a running man, or of a football when kicked, or of a railway train when the engine draws it along, are all cases of molar motion. But a finer kind of movement has of late years come within the ken of mankind. It has been at work probably eternally. It is molecular movement, or movement of small masses. But only very recently has the mind of man been able to take cognisance of this form. The researches of the physicists, the chemists, the biologists have demonstrated that there is a whole world of movements that affect only the minute particles of bodies. Thus heat is a mode of motion; electricity is another; magnetism is a third. The familiar phenomena of light are no longer regarded as due to any actual matter that has been thrown from a luminous body. They are the result of waves of a fluid imponderable and universal called ether, and there seems every reason to believe that the phenomena commonly called vital are of the same or of a Kindred order. Life, it would appear, is but a mode of motion. And though we know life generally only by its manifestations of molar motion, as in the blow of the arm, or the stride of the leg, yet these massive movements are but the outward representatives of a large number of internal movements, of chemical nature in digestion, of nervous nature in the sense-organs and nerve tissues. Every bodily movement visible to the ordinary eye is only the obverse aspect of many molecular motions, not as yet visible to man. The reasons why we regard matter and motion as all-sufficient in the explanation of all the phenomena of the universe are several. In the first place, no destruction of matter has ever been witnessed. Second, no destruction of motion, has ever been witnessed. The creation of either matter or motion has been equally unseen. Transformations of matter from one of its infinitely many forms to some other are constantly visible, and they are always unattended by the smallest increase or diminution in the actual quantity of matter. So also with motion--transformations without any change in quantity are continually occurring. Thus, we see the rocks disintegrated by the action of rain and running water, "weathered" by the action of the air. We see the matter of which they consisted worn away and carried down by streams and rivers to be deposited at the mouths of rivers or on the beds of seas. Or we set fire to a candle and watch its matter combining with the matter of the air to form the products of combustion, carbon, dioxide, steam, and their fellows. Or a dead animal or plant is seen to decay slowly into these same gases that the burning candle gives forth and into certain inorganic salts. And these are all cases of the transformation of matter without any creation or destruction.