There is also another thing that must be taken into account. Science teaches that all matter is in vibration. Indeed, philosophy points to the theory that matter itself is nothing more than centers of force in vibration. The lowest vibration we know is that of sound. Then comes, at an enormously higher rate, heat, light (beginning at dark red and passing through the prismatic colors to violet which has a high vibration), to the chemical rays, and then the so-called X or unknown rays which have a much higher vibration still. Electricity is a form of vibration, and according to the belief of many scientists, life is a species of vibration so high that we have no possible means of measuring it. As every student of science knows, air appears to be the chief medium for conveying vibration of sound, metal is the chief medium for conveying electric vibrations, while to account for the vibrations of heat and light we have to assume (or imagine) an invisible, imponderable ether which fills all space and has no property of matter that we can distinguish except that of conveying vibrations of light in its various forms. When we pass on to human life, we have to theorize chiefly by analogy. (It must not be forgotten, however, that the existence of the ether and many assumed facts in science are only theories which have come to be generally adopted because they explain phenomena of all kinds better than any other theories which have been offered.) Now, in life, as in physical science, any one who can get, or has by nature, the key-note of another nature, has a tremendous power over that other nature. The following story illustrates what this power is in the physical world. While we cannot vouch for the exact truth of the details of the story, there can be no doubt of the accuracy of the principle on which it is based: “A musical genius came to the Suspension Bridge at Niagara Falls, and asked permission to cross; but as he had no money, his request was contemptuously refused. He stepped away from the entrance, and, drawing his violin from his case, began sounding notes up and down the scale. He finally discovered, by the thrill that sent a tremor through the mighty structure, that he had found the note on which the great cable that upheld the mass, was keyed. He drew his bow across the string of the violin again, and the colossal wire, as if under the spell of a magician, responded with a throb that sent a wave through its enormous length. He sounded the note again and again, and the cable that was dormant under the strain of loaded teams and monster engines—the cable that remained stolid under the pressure of human traffic, and the heavy tread of commerce, thrilled and surged and shook itself, as mad waves of vibration coursed over its length, and it tore at its slack, until like a foam-crested wave of the sea, it shook the towers at either end, or, like some sentient animal, it tugged at its fetters and longed to be free.