6th. These same researches have enabled Keely to pronounce definitely as to the nature of what is recognized as gravity, an ever-existing, eternal force, coexistent with the compound etheric, or high luminous, entering into all forms of aggregated matter at their birth. Keely thinks that gravity is the source from which all visible matter springs, and that the sympathetic or neutral centre of such aggregation becomes at birth a connective concordant link to all neutral centres that have preceded it and to all that may succeed it, and that disturbance of equilibrium, like gravity, is an ever-existing force. His researches in the vibratory subdivision of matter have revealed to him some of the mysteries of the hidden sympathetic world, teaching that "the visible world," as Coleridge wrote, "is but the clothing of the invisible world;" that "true philosophy," as Professor George Bush said, "when reached will conduct us into the realm of the spiritual as the true region of causes, disclosing new and unthought-of relations between the world of matter and of mind." Professor Thurston writes, in the January number of the North American Review, "We are continually expecting to see a limit reached by the discoverer, and by the inventor, and are as constantly finding that we are simply on a frontier which is being steadily pushed further and further out into the infinite unknown. The border-land is still ahead of us, constantly enlarging as we move on. The more we gain, the more is seen to be achievable." All planetary masses Keely calls terrestrial, showing in his writings that the beauty of the celestial concordant chords of sympathy forming the harmonious connective link, in what may be denominated "the music of the spheres," is seen in the alternate oscillating range of motion between the planetary systems; for at a certain range of the greater distance, harmony is established, and the attractive forces are brought into action, under the command, "Thus far shalt thou go, and no further." Then in the return towards the neutral centres, when at the nearest point to each other, the opposite or propulsive force is brought into play; and "thus near shalt thou come, and no nearer;" advancing and receding under the celestial law of etheric compensation and restoration, as originally established by the Great Creator.