Chapter Iv., Where the Author Has Postulated Atomicity, Heaviness or

weight, density, elasticity, inertia, and compressibility for the aether, and so brought the theory of the aether into perfect harmony with all observation and experiments relative to ordinary matter. It will be shown that Clerk Maxwell also definitely affirms the atomicity of the aether, while Tyndall and Huyghens also use the term "particles of aether" over and over again.

Moreover, in view of the most recent researches in electricity made by Sir William Crookes and Professor J. J. Thomson, we are compelled to accept an atomic basis for electricity, and as Dr. Lodge, in his Modern Views of Electricity, states that "Aether is made up of positive and negative electricity," then, unless we postulate atomicity for the aether, we have to suppose that it is possible for a non-atomic body (aether) to be made up of atoms or corpuscles, which conclusion is absurd, and therefore must be rejected as illogical and unphilosophical.

After postulating atomicity for the aether, we are then able to apply the Newtonian Law of Gravitation to it, which distinctly affirms that "every particle of matter attracts every other particle," and so we arrive at Thomas Young's fourth hypothesis given in the Philosophical Transactions of 1802, where he asserts that "All material bodies have an attraction for the aetherial medium, by means of which it is accumulated within their substance, and for a small distance around them in a state of greater density." He adds the significant remark that this hypothesis is opposed to that of Newton's. With an atomic and gravitative aether it is shown in Chapter IV. how the elasticity, density, and inertia of the medium are brought into harmony with all observation and experiments.

In the succeeding chapters the new theory is applied to the phenomena of heat, light, electricity, and magnetism, and the principles enunciated therein are then applied to solar and stellar phenomena.

One of the greatest stumbling-blocks to the discovery of the physical cause of gravitation, apart from the unphilosophical theory of the aether medium, lies in the fact that apparently the Law of Gravitation only recognizes a force of one kind. Dr. Lodge refers to this phase of the subject on page 39 of his Modern Views of Matter just published. It is here where scientists have failed to solve the problem of universal gravitation, as there are two forces at work in the solar system and not one; that is, if we are to accept the results of up-to-date experiments in relation to radiant light and heat as performed by Professor Lebedew, and Nichols and Hull of America. Their experiments conclusively prove that light waves exert a pressure upon all bodies on which they fall, and by no reasoning can this pressure be resolved into an attractive force.

Herschel in his Lectures on Scientific Subjects definitely refers to the existence of a repulsive force in the solar system, and asserts that it offers the most interesting prospect of any future discovery.

The author has therefore attacked the problem of the cause of gravitation, by trying to solve the problem of the cause of the repulsive force which has been experimentally demonstrated to exist by Professor Lebedew and others.

In his efforts to ascertain the physical cause of the Centrifugal Force, he has been assisted by an unknown and original essay written by an unknown writer over twenty years ago. That unknown writer was the author's father, who wrote an essay on the Complementary Law of Gravitation, and if it had not been for that essay, the present work would never have been attempted.

The main object of the author in Chapters VI., VII., and VIII., is to prove beyond the possibility of contradiction, from the phenomena of heat, light, and electricity, the existence of two forces in the solar system; and by so doing, to bring our philosophy of the aether medium, and all gravitational phenomena, into harmony with all observation and experiments, which at present is not the case. In seeking to do this he found that the new theory of the aether harmonized with views given, by Faraday and Clerk Maxwell in relation to electric and magnetic phenomena, and by the new theory Maxwell's hypothesis of "Physical Lines of Force" receives a definite and physical basis. In Chapter X. the author endeavours to show what the Electro-Kinetic energy is, which term is used by Clerk Maxwell, the term being brought for the first time into harmony with our experience. The Electro-Magnetic Theory of Light also receives fresh light from the new theory of an atomic and gravitating aether.

In the succeeding chapters the theory is applied to Newton's Laws of Motion and Kepler's Laws, and is found to harmonize with all the results given by these laws. Such a result is a distinct advance on the application of a frictionless aether to solar and stellar phenomena, as it is impossible for Kepler's Laws to be reconciled in any way with our present theory of the aether.

In the concluding chapter on the unity of the universe, certain views are suggested as to the ultimate constitution of all matter, upon an aetherial basis, which hypothesis practically resolves itself into an electric basis for all matter. It is suggested that aether and electricity are one and the same medium, both being a form of matter, and both possessing exactly the same properties, viz. atomicity, weight, density, elasticity, inertia, and compressibility. This view of matter harmonizes with the most "Modern Views of Matter" as suggested by Sir Oliver Lodge in his Romanes Lecture 1903.

The author has accepted Newton's way of spelling "aether" as given in his work on Optics, and has given "aetherial" the same suffix as "material," in order to differentiate the word from "ethereal," which is too metaphysical a term for a material medium.

Nottingham, Sept. 1903.

CONTENTS