Its principal modern use is to account for the transmission of Light from the Sun and Stars to the Earth. It was held that a thing could not act "where it was not," and so it became necessary to account for the transmission either by the theory that small particles of substance were thrown off from the Sun, and travelled to the Earth, or else that there was some medium of communication by means of vibrations, etc. Newton held to the first theory, but his hypothesis went down before the Ether advocates, who advanced the "wave-theory," although it seems that, like Banquo's ghost, Newton's theory will not stay down, and is now taking on a new lease of life, owing to the discovery of the Corpuscle and Radiant Matter. The Wave-theory philosophers asserted that the Light and Heat of the Sun were thrown off in the shape of Force or Energy, and transformed into "waves" in and of a hypothetical Ether (Aristotle's own), which waves were carried to the Earth, where, meeting Substance, they were again transformed into Heat and Light. It was known that Light and Heat travelled at the rate of 184,000 miles per second, and therefore the "waves" of the Ether were considered to have that speed. The Wave-theory seemed to fit the facts of the case better than the Newtonian Theory of Corpuscles, although the latter has always been considered as better explaining certain phenomena than the new theory. And so the Ether Wave became generally accepted, and remains so to-day, although recent discoveries are causing a disturbance in the scientific camp regarding the question. Later it was discovered that the Electricity travelled at the same rate as Light and Heat, and the Wave-of-the-Ether theory was thus thought to have additional verification, and Electricity came under the Law and remained there until the Electron discovery, which is causing much disturbance, among those interested in the study of Electricity. Briefly stated, the theory of the Universal Ether is this: That pervading all Space in the Universe--not only between planets, stars and suns, but also "filling in the cracks" between molecules, and atoms as well--there is a subtle Substance in and through which the waves of Light, Heat, Electricity and Magnetism travel at the rate of 184,000 miles per second. This Substance is said to be "Matter that is not Matter"--in fact, Science does not venture to say just _what_ it is, although it freely states just what some of its properties must be, and, alas! these properties are most contradictory and opposite to each other, as we shall see as we proceed.