Chapter IV: Aether Is Matter (1)

ART. 42. _Aether is Matter._--The hypothesis of an Aether which fills all space was made in order that scientists might be able to account for certain phenomena of Light, which otherwise were difficult to account for. Its existence is demanded not only for the phenomena of Light, and Heat, but, in view of the comparatively recent researches of Hertz on "Electric Waves," of Electricity also.

The Aetherial Medium is generally assumed to be that fundamental medium, by means of which possibly all the properties of matter, and all the phenomena of motion of the universe are to be explained. Light and Heat have been proved to be due to the periodic wave-motion of this universal Aether, while from the investigations and researches of such men as Clerk Maxwell, Poynting, Thompson and Hertz, it has been proved that electro-magnetic phenomena are due to this same medium.

Several different forms of Aether have been postulated by various philosophers from time to time, but the only Aether that has survived, is that which was first conceived by Huyghens to explain the phenomena of Light, though it was Thomas Young who finally succeeded in placing the conception of the Aether on a sound basis. Each discovery of science has only strengthened the hypothesis and existence of the Aether, the latest discovery, that of wireless telegraphy so successfully developed by Signor Marconi, being attributed to the electro-magnetic properties of this self-same Aether.

It has already been pointed out that Newton endeavoured to account for Gravitation by the pressure of the Aether. If, therefore, Gravitation be really due to this universal medium it becomes necessary to ask ourselves, What are the properties and characteristic qualities of this wonderful medium? What then is Aether, and what its properties?

It has already been pointed out in Art. 29 that Aether is matter. Such an assumption is strictly in accordance with the Rules of Philosophy, quoted in Chap. I.

Not only is this hypothesis a simple one, but it is also in accord with all our experience and observation.

It is a simple supposition, because, unless Aether is assumed to be matter, then, instead of the universe being composed of two classes of things, matter and motion, we have to add a third class, which we call Aether. It can be readily seen, that by the introduction of a third class into the composition of the universe, such an addition, instead of simplifying the constitution of the universe, adds greater complexity to the same.

By accepting the hypothesis that Aether is matter, we do away with the third class of essentials in the universe, and so reduce the number to two classes. If we could go one step further, and prove that instead of there being two classes of things in the universe, there was only one group, and show that all material things, and all phenomena could come under the head of either matter, or motion, then we should have reduced the universe to the simplest conception possible. As, however, it is not possible, at least in our present state of knowledge, for us to come to this fundamental and simple hypothesis of unity for the entire universe, we must accept the next simpler solution, and affirm that the universe is composed of two classes of things, viz. matter and motion, and this as I have already shown is a simpler classification than by putting Aether into a class by itself, and therefore is in accord with our first Rule of Philosophy.

Again, it is entirely in accord with our second Rule of Philosophy, as it in no way violates the results of experiment, experience, or observation. Look where we will, or at what we will, whatever we see, touch, taste, or smell is termed matter. The burning sun, the glowing star, the flying meteor, the glowing comet, the earth, our own island home, the towering rock, the wide ocean, the running river, the green trees of the forest, the tiny insect, the lordly elephant, all animals, plants, and our own physical body, all are composed of matter, either in solid, liquid or gaseous form. Therefore when we affirm that Aether is matter, the affirmation is strictly in accordance with the elementary principles of Philosophy, and in no way violates their rules or laws. To affirm that Aether is not matter, is to affirm something contrary to all experience, unless it be affirmed that Aether is motion, for which assumption the evidence is not nearly so strong or conclusive as that it is matter. Therefore the objector to this assumption is himself unphilosophical, in that he postulates or supposes that the Aether is a medium, with qualities which lie altogether outside the range of our experience and observation.

There is a growing conviction in the minds of scientific men, that Aether belongs to that group of things which we describe by the term matter. Lord Kelvin in giving an address to the British Association, 1901, on "Clustering of Gravitational Matter in any part of the Universe," said: "We are all convinced with our President (Professor Rucker) that _Aether is Matter_. Aether we relegate to a distinct species of matter which has inertia, rigidity, elasticity, compressibility, but not heaviness."

Dr. Larmor in _Aether and Matter_ writes: "Matter must be constituted of isolated portions, each of which is of necessity a permanent nucleus belonging to the Aether, of some such type as is represented for example by a minute vortex ring in a perfect fluid."

Faraday in relation to this subject writes (_Exp. Res._, vol. ii.): "The view now stated of the composition of matter would seem to involve the conclusion that matter fills all space, or at least all space to which Gravitation extends, _including the sun and its system_, for Gravitation is a property of matter dependable on a certain Force, and it is this Force which constitutes matter." As the Aether fills all space, including the solar system, therefore, according to Faraday, "Aether must also be Matter."

By the hypothesis that Aether is matter, with all the properties that such a hypothesis logically gives to Aether, I venture to premise that the third Rule of Philosophy will be fulfilled, and that there is no phenomenon of the astronomical world, and no part of the universal Law of Gravitation which such a hypothesis will fail to account for on a satisfactory physical basis. For the first time a physical explanation will be given to Newton's Laws of Motion, at least to those laws which are strictly in accordance with the first and second Rules of Philosophy. For the first time a physical conception will be given to all Kepler's Laws, and what the mathematical Laws of Gravitation have done to Kepler's Laws, in giving them a mathematical basis, the simple hypothesis that Aether is matter, with all that is logically involved therein, will do for the same laws from the physical standpoint. For the first time a physical conception will be given to the Centrifugal and Centripetal Forces, which are the complement and the counterpart of each other, that physical conception being the outcome of the same hypothesis that Aether is matter.

In addition to this, light is thrown upon such problems as are referred to by Lord Kelvin (_Phil. Mag._, July 1902) in his paper on "Clouds on the Undulatory Theory of Light," and further light is given to some theories of Electricity advanced by such men as Faraday, Clerk Maxwell, and Professor Thompson. I venture to think, therefore, that the hypothesis advanced, and the conception put forward that Aether is matter, is philosophically correct, and is warranted by the results that arise out of such a hypothesis.

It may be thought by some that the hypothesis that I have advanced is already conceded, and that the fact that Aether is matter is already admitted by scientists and advanced thinkers generally. But such an idea is only partly correct. It is already admitted by some of our most advanced scientists that Aether is matter, but that admission is only carried partially to its logical conclusion.

Lord Kelvin in an address to the British Association, 1901, gave utterance to the following remarks on the relation of Aether to Matter: "We are convinced with our President (Professor Rucker) that Aether is Matter, but we are forced to say that the properties of Matter are not to be looked for in Aether, as generally known to us by action resulting from force between atoms of Matter and atoms of Aether. _Here I am_ ILLOGICAL _when I say between Matter and Aether_, as if Aether were not Matter. Aether we relegate to a distinct species of Matter which has inertia, rigidity, elasticity, compressibility, but NOT HEAVINESS."

From a quotation of this kind, which is from the lips of one of the keenest intellects of the present time, I think I am justified when I make the statement, that it is not conceded that Aether is matter, with all that that concession logically involves. Because, as Lord Kelvin points out, though it is admitted that Aether is matter, yet that admission is only a qualified admission, and not one which carries with it all the properties that essentially belong to matter, or an admission which includes the fact that Aether is gravitative, that is, subject to Gravitation. To be strictly logical and philosophical, in the statement that Aether is matter, it must be conceded not only that Aether is subject to such properties as elasticity, inertia, and compressibility, but that it is also gravitative or possesses weight. For either Aether is matter, or it is not matter.

It cannot be both at one and the same time. Such a conception is altogether opposed to that simplicity which is the chief characteristic of Nature as pointed out by Newton.

If therefore Aether be matter, then, to be strictly logical and philosophical, it must be conceded that Aether is gravitative, as well as having the other properties of matter, as elasticity and inertia, etc. Unless this is conceded, then we have the anomaly in Nature of matter, which is not matter, because it violates the very principles which above all others decide what is matter, viz., "That every particle of matter attracts every other particle," etc., that is, that it is gravitative. Thus by supposing that the Aether is matter, and yet not being gravitative, all the Rules of Philosophy are violated, as such a hypothesis is opposed to both the first and second Rules of Philosophy, and is contrary to all observation and experience. If Aether therefore be matter, as is conceded by the most advanced thinkers of the time, then it follows that the only logical and philosophical conclusion that can be arrived at is, that it is also subject to those properties which are the chief characteristics of all matter. These properties may be classified as follows: atomicity, gravitation, density, elasticity, inertia, and compressibility.

ART. 43. _Aether is Universal._--Young in his first Hypothesis on the Aether medium states that, "A Luminiferous Aether pervades the Universe rare and elastic in a high degree" (_Phil. Tran._, 1802).

As Young points out, this invisible and elastic Aether fills all space and floods the universe at large. In it suns blaze, stars shine, worlds and planets roll, meteors flash, and comets rush in their mysterious flight. In it all material and physical things exist, for it is to them not only the primary medium of their existence, but, just as the infinite and ever-active energy of the Divine is to the universe in its entirety and fulness, the exciting and stimulating spirit of its energies and powers, so this aetherial ocean is to the material and physical universe, the exciting and stimulating medium of all its activities, energies, and powers; and without which, though all material and physical things were endowed with the varied capacities of their kind or life, yet they could neither exert nor exercise them, nor even exhibit the simple activity of motion. Hence everywhere, where material and physical things are, there, as the medium of their existence and energy, the Aether is; and where the Aether is not, no material or physical thing is, or can be. That the Aether is universal is proved by the phenomena of light. Light-waves have a velocity of about 186,000 miles per second. Now the distance of the sun from the earth is about 92,000,000 of miles, so that light takes about eight minutes and a half to travel from the sun to the earth.

A ray of light from the nearest fixed star takes about three and a half years to reach the earth, while there are some stars so far away that astronomers tell us, that though light travels with so great a velocity, yet it would take several thousand years to reach the earth. This fact implies that throughout boundless space there is to be found this aetherial medium. Thus interplanetary and interstellar space is not empty, but is filled with this ever-present, all-pervading Aether; and not only so, but every particle of matter in the universe is surrounded by this universal Aether, which forms the exciting and stimulating medium of all the activities, energies, and motions of all Matter. Thus the Aether is both universal and infinite in its extent.

Clerk Maxwell, in his paper on "Action at a Distance" (_Collected Works_, by Niven), with reference to the universality of the Aether, writes: "The vast interplanetary and interstellar regions will no longer be regarded as waste places in the universe, which the Creator has not seen fit to fill with the symbols of the manifold order of His Kingdom. We shall find them to be full of this wonderful medium, so full, that no human power can remove it from the smallest portion of space, or produce the slightest flaw in its infinite continuity. It extends unbroken from star to star, and when a molecule of hydrogen vibrates in the Dog Star, the medium receives the impulses of those vibrations, and transmits them to distant worlds. But the medium has other functions besides bearing light from world to world, and giving evidence of the absolute unity of the material system of the universe. Its minute parts may have rotatory as well as vibratory motions, and the axes of rotation form those lines of magnetic force which extend in unbroken continuity into regions which no eye has seen, and which, by their action on our magnets, are telling us in language not yet interpreted what is going on in the hidden world from century to century." Now I premise, that in the theory of the Aether to be submitted in this work, the physical interpretation of this statement of Maxwell's will receive its literal fulfilment.

ART. 44. _Aether is Atomic._--If there is one fundamental truth which is applicable to all matter, it is, that all matter is atomic.

Professor Rucker, in his Presidential Address to the British Association of 1901, in dealing with this question, said: "The believer in the atomic theory asserts that matter exists in a particular state, that it consists of parts which are separate and distinct from one another, and as such are capable of independent movement. It is certain that matter consists of discrete parts in a state of motion, which can penetrate into spaces between the corresponding parts of surrounding bodies. Every great advance in chemical knowledge during the last ninety years finds its interpretation in Dalton's Atomic Theory."

From such an authority as this, and from the facts which he gave in his dealing with the question, we are bound to admit that all matter is atomic. That being granted, when the statement is made, therefore, that Aether is matter, the only logical conclusion that can be arrived at, with reference to the question of the atomicity of the Aether, is, that Aether is also atomic. Unless this be conceded, we have the first and second rules of our Philosophy violated, as an atomless Aether is opposed to that simplicity of conception, which is an essential requirement of all hypotheses, and is moreover contrary to that presumptive evidence gathered from observation and experiment, which teaches us that all matter is atomic. If it be argued, that it is impossible to decide upon a question as to the atomicity of the Aether, my reply is that the same argument may reasonably be applied to all matter. But, as Professor Rucker stated, all the evidence on matter points out and supports the theory of its atomicity, and, therefore, the only logical and philosophical conclusion is, that Aether is atomic also. Again, it may be suggested that we cannot see or touch an atom of Aether, and that it is not only invisible, but apparently incapable of being made sensible to our senses. In reply to that, as I have already shown in Art. 31, that objection can be equally used against an atom of hydrogen, or an atom of oxygen. Does any one doubt the existence of the hydrogen atom or the atom of oxygen, because it is invisible to the sense of sight, or cannot be revealed to the limited sense of touch? Certainly not! By the same reasoning, it is just as illogical to deny the existence of an atom of Aether because it cannot be seen or felt, as it is to deny the existence of an atom of hydrogen or oxygen. An atom of Aether reveals itself to the senses in the same way that an atom of hydrogen or oxygen does, that is, by the force or energy which it exerts. Its vibrations can be manifested to the body in the form of heat, while the undulatory motion which the aetherial atoms transmit in the form of light, reveal the presence of the aetherial atom to the sense of sight. The question at once arises as to what constitutes an aetherial atom, what are its properties and motions?

Now, in order for us to enter successfully into this speculative region, it is essential that we should, as far as possible, conform to the Rules of Philosophy, and endeavour to gain some conception of an aetherial atom from the results of experience and observation. In doing this, we are at once confronted with the difficulty, that no one has ever seen an atom, or analyzed the properties of one. Actual experiment has revealed nothing absolutely certain as to the ultimate character of an atom, and if this be true of the atoms of matter, then it must also be true of an aetherial atom. It would seem at first, therefore, that we have no results of experiment, or observation, by which we may be guided in formulating a right conception as to the constitution of an aetherial atom, and therefore we are thrown simply into the regions of speculation as to its constitution and properties.

But I venture to suggest, that there is a method which is strictly philosophical in its application, by which we may possibly arrive at a clear conception of an aetherial atom. All great discoveries of science have been the outcome of applying the principle, that what is true of the visible and seen, is true of the invisible and unseen; that what is true of the known, is true of the unknown; that the principles and laws which govern the small also govern the large and the great. It was thus that Newton discovered his great Law of Gravitation, as he was able from the falling of an apple, to rise to the application of the same principle to our satellite the moon, and this led him on to the discovery of the Law of Gravitation.

If, therefore, in Philosophy, the laws governing the small things are also applicable to the great things, then the converse equally holds good, that the laws governing great things are the reflex of the laws which govern the small things. For example, the laws which govern the light and heat of the sun are the same which govern the light and heat of a candle or a glow-worm; and the laws which govern a planet or world are the same as those which govern an atom. Thus a planet or world, which is simply an agglomeration of atoms, may reveal to us in its motions and laws, what are the motions and laws which govern the atomic world.

In looking at the properties and motions of a planet, therefore, as our earth for example, we find that a planet is a sphere, or more correctly an oblate spheroid; that the earth or planet is a magnet possessing polarity, having a north and south pole; that it has rotation on an axis, in addition to translation in an orbit, and that it is subject to the universal Law of Gravitation.

If, therefore, it holds good in Philosophy, that the small things are the index to the greater, and that the laws governing the small things also govern the greater, then the converse holds good, that what is true of the large is true of the small, and that the laws governing the great also govern the small.

So that gathering up those chief properties of the earth to which I have already referred, and applying them to an aetherial atom, or any other atom if necessary, we arrive at the conclusion that an atom must be spherical in shape, must possess rotation, and must have an orbit, must possess polarity, and also be subject to the universal Law of Gravitation.

Here, then, we have given to us certain data by which we are enabled to form our conception of an atom, aetherial or otherwise. The question arises, whether, among the forms of atoms which have been devised by scientists, any of the atoms so conceived fulfil all, or nearly all of these requirements. We have Boscovitch's Atom, the Hard Atom of Lucretius, and the more recent conception of the Vortex Atom of Lord Kelvin. Of all the hypotheses in regard to the ultimate nature and constitution of an atom, the Vortex Theory probably is the one which offers to the mind the simplest conception of an aetherial atom.

The Vortex Ring Atom, however, which has been so fully developed by Lord Kelvin, hardly fulfils all the requirements of an aetherial atom. In the first place it is not spherical in shape, and I hold that to be one of the fundamental bases of the aetherial atom. Then, in the next place it does not, so far as I can read, possess polarity; that is, it does not possess a north and south pole, through being a magnet in the same way as the earth is a magnet. We must therefore look for a modification of the vortex ring to discover the constitution of our aetherial atom, and I venture to think that such a modification is to be found in Professor Hill's conception of a Spherical Vortex Atom (_Phil. Trans._, 1894).

In the conception there put forward, and mathematically worked out, Professor Hill showed that his spherical vortex atom possessed similar properties and characteristics to the vortex rings of Lord Kelvin. So that the spherical vortex atom would possess rotation on an axis, and it would be a magnet, as I shall prove later on, because it rotates in an electro-magnetic medium. It would possess elasticity, compressibility, inertia, and, further, would possess a certain amount of mass. That mass might be infinitely small, but nevertheless it would possess mass of an infinitesimal order.

Further, if we are to be strictly correct, in our analogy between the earth and the aetherial atom, its polar diameter must be shorter than its equatorial diameter, as that is one of the facts observable regarding the shape of our earth, so that the shape of the aetherial atom will not be strictly spherical, but its actual shape would be that of an oblate spheroid, being flatter at the poles, and bulging out in the equatorial regions.

This exact analogy between the earth and an aetherial atom may not at present seem of very great importance, but its importance will be seen later on, when we come to deal with the phenomena of heat, light, and electricity.

Here, then, is our conception of an aetherial atom in the rough, based not upon any imaginative hypothesis, but rather upon that strict conformity to observation and experience, which is the very groundwork of all true Philosophy.

For, after all, what is the earth but an atom on a large scale? In comparison with illimitable space, with its infinite distances, that can alone be measured by the velocity of light, our own earth is but a speck of dust, a very atom that helps to make up the universe, and, as such, should teach us the shape and properties of other atoms of which the same universe is composed.

We have therefore to conceive of the all-space-pervading Aether as being composed of infinitesimal portions of Aether, which are nearly spherical in shape, and ever in a state of rotation; this state of rotation differentiating the atom of Aether from the free Aether, if such an entity exists. So that an atom of Aether would simply be an infinitesimal portion of the Aether in a state of rotation.

If, by any means, we could stop the rotation, we should at once destroy the atom, in the same way that the smoke vortex ring would cease to be a ring, if its rotation were stopped. The cessation of the rotation I, however, believe to be impossible. So that even in the ultimate atom of that universal medium the Aether, we have an illustration of the combination of those two forms which are inseparably connected throughout the whole universe, viz. matter and motion, and it is the combination of these two that gives to the aetherial atom its form, and its very existence, without which it has no life, and ceases to exist.

It may be necessary in the development of this work as we proceed, to slightly modify our conception of the aetherial atom, but that modification will rather be of a constructive character, than a destructive one. There may also be certain objections to meet and explain away when we deal with the phenomena of light, heat, and electricity, and Gravitation, and the part which the aetherial atom plays in those phenomena, but these objections I hope to meet and answer as they arise.

The atomicity of the Aether has already been suggested by such scientists as Clerk Maxwell, Lord Kelvin, Dr. Larmor, and Professors Lodge and J. J. Thompson. Clerk Maxwell, in an article on "Action at a Distance,"[3] referring to the atomicity of the Aether, writes: "Its minute parts may have rotatory as well as vibratory motions, and the axes of rotation may form those lines of magnetic force which extend in unbroken continuity into regions which no eye has seen." I premise that I will conclusively prove that this statement finds its literal fulfilment in the theory of the Aether that will be developed in this work.

Lord Kelvin, in several articles on "Vortex Motion" in the Philosophical Magazines of recent years, has mathematically dealt with the Aether from the atomic standpoint, and has endeavoured to prove that the Aether medium is composed of vortex rings, but he was unable to come to any satisfactory conclusion. With the theory that Aether is matter, and therefore possesses mass, his conception is now brought within the range of physical explanation, as well as mathematical calculation.

Dr. Larmor, in his _Aether and Matter_, has successfully applied the principle of the atomicity to the Aether, on what is termed the "Electron" basis. He states that an electron is nothing more or less than "a point singularity in the electro-dynamic and optical Aether." So that our aetherial atom is practically synonymous with Dr. Larmor's electron. Again, Dr. Larmor, in the same work, states that "the atomicity of electricity is coming within the scope of direct experiment."[4] But Professor Lodge, in his _Modern Views of Electricity_, states that "the Aether is composed of positive and negative electricity, the combination of these two forming the Aether medium."[5] Now, if the Aether is composed of positive and negative electricity, and the atomicity of electricity is coming within the scope of direct experiment, it follows as a matter of necessity that the atomicity of Aether and the atomicity of electricity are one and the same, and therefore the atomicity of Aether is coming within the scope of direct experiment. Professor J. J. Thompson, who has also attacked the problem of the atomicity of electricity, speaks of "corpuscles" which are the actual carriers of the positive and negative electricity, in the atoms of the various elements. These corpuscles therefore indicate the fact that electricity has an atomic basis.

Now if there is any such identity between Aether and electricity, as there undoubtedly is, and electricity has an atomic basis, then the atomicity of the Aether follows as a matter of course, otherwise we shall have a medium composed of atoms which is itself not atomic, which conclusion is absurd and therefore unphilosophical. So that the most recent researches into electricity confirm and establish the atomicity of the Aether.

[Footnote 3: _Collected Works_, by Niven.]

[Footnote 4: Preface to _Aether and Matter_.]

[Footnote 5: Page 348.]

ART. 45. _Aether is Gravitative._--Young, in the _Philosophical Trans._ of 1802, in regard to this question, states in his Fourth Hypothesis: "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, but not greater elasticity." He adds that "this fourth hypothesis is opposed to that of Newton's."

Scientific research has justified the conception of his first three hypotheses with respect to the universality, elasticity and vibrations of the aetherial medium, but up to the present I am not aware that science has accepted his fourth hypothesis.

I propose to show how, from a strictly philosophical and logical standpoint, his fourth hypothesis is just as true as his first three hypotheses, and that it henceforth passes out of the realm of the hypothetical into the realms of fact and science, not only by philosophical reasoning, but by actual experiment made by some of the most advanced scientists of the present time.

Let us consider the question first from the standpoint of the Rules of Philosophy. Our first Rule of Philosophy states, that any hypothesis must be simple in connection. Now I put it to any intelligent man, and ask him which is the simpler conception of Aether? To affirm that Aether is matter, and therefore subject to the properties of matter, as elasticity, density, inertia and Gravitation, or to affirm that Aether is matter, but while it is subject to some of the properties of matter, as elasticity, density and inertia, it is not subject to the very property which of all properties is the most fundamental, viz. Gravitation. There can, in my opinion, only be one answer to the question, so that, when we affirm that Aether is matter, we are compelled to affirm, in order to conform to the first Rule of Philosophy, that it is gravitative also. Faraday was also of the opinion that Aether was subject to the Law of Gravity, for, writing in _Experimental Researches_, he states: "The view now stated of the constitution of matter, would seem to involve the conclusion, that matter fills all space, or at least all space to which Gravitation extends, INCLUDING THE SUN AND ITS SYSTEM. For Gravitation is a property of matter, dependable on a certain force, and it is this force which constitutes matter."

Let us also test the question by our second Rule of Philosophy, and we shall find greater evidence still for the statement that Aether is gravitative. What do experience and observation teach us with reference to matter? As we have already seen (Art. 37), if there is one truth that they teach us regarding matter, it is that it is gravitative.

There is not the slightest evidence throughout the universe, as far as our observation can lead us to form an opinion, that there is any kind of matter which is not subject to the Law of Gravitation. Therefore to assume that Aether is matter, and yet not to assume that it is also subject to Gravitation, is to assume that which is directly opposed to the most fundamental principle of all philosophical teaching and scientific research. If Aether be matter, therefore, and yet is not gravitative, we shall have an anomaly in an otherwise universal law, as we shall have some kind of matter which fails to come within the scope of the universal Law of Gravitation.

To be consistent, therefore, we must either cease to call Aether matter, or else admit that Aether, like all other matter, is gravitative. It is absolutely impossible to be strictly logical and admit that Aether is matter, and not to admit that it is subject to the most universal law that governs matter, as the Law of Gravitation distinctly states that "every particle or atom of matter attracts every other particle." This universal law in view of a gravitationless Aether would have to be amended to "Some particles of matter attract some other particles." Thus the universal Law of Gravitation ceases at once to be a universal law, and such a result is opposed to all experience and experiment. Again, let us apply our third Rule of Philosophy to this supposed gravitationless Aether, and see what the result is.

Our third rule states, that any hypothesis put forward must satisfactorily account for the phenomena sought to be explained and accounted for. The Aether was conceived in order to explain the phenomena of light, and one of the properties it was conceived to possess was elasticity, yet that very conception was devoid of the most fundamental property of matter, without which there is no elasticity, that is, that it was not atomic.

I have already shown in Art. 44, that Aether is atomic, and therefore there is given to the Aether a structure which is capable of exhibiting elasticity, inertia, density, and even Gravitation, while at the same time, the conception is fully in harmony with philosophical reasoning and Newton's Rules of Philosophy.

Let us consider the question whether Aether is, or is not gravitative, from another aspect. For several hundred years, the physical cause of Gravitation has been outstanding, while the world has held the conception that Aether is a gravitationless and frictionless medium. The earth has been rolling on in her orbit year in, year out, together with all the other planets in their annual march round the sun, and yet through all that time no one has been able to suggest, or give any satisfactory or adequate physical explanation, as to what moves the earth along.

I am fully aware that Newton suggested and proved, that it was because of the Law of Gravitation. But I look upon that as a mathematical explanation and not as a physical one.

Now I venture to predict this, that on the assumption of a gravitationless medium, the physical explanation so longed for will always be outstanding, as a gravitationless Aether is synonymous with a frictionless medium, and so long as we admit that there is a frictionless medium, so long will the physical cause of Gravitation, and therefore the physical cause of all the movements of the planets and comets, be outstanding and unexplained.

If, however, instead of being illogical in our reasoning, we become logical, and affirm that Aether is matter, and because all matter is gravitative, therefore Aether is gravitative; and if, instead of being unphilosophical, we become philosophical, and affirm that because a gravitationless Aether violates both the first and second Rules of Philosophy, such a conception must be put away, and in its place a more philosophical conception must be forthcoming, which is that Aether is gravitative; then, upon such a logical and philosophical basis, I venture to premise that the great problem which is still outstanding of the cause of Gravitation, will remain outstanding no longer, and the physical cause of all the movements of all celestial bodies will be put upon a physical basis, in addition to a mathematical one.

If such a result can be arrived at by the logical and philosophical conception of a gravitative Aether, then the three Rules of Philosophy are fully satisfied, and the assumption of a gravitative Aether is warranted on a strictly philosophical basis.

So that Thomas Young is strictly correct from a philosophical standpoint in his fourth hypothesis, when he states: "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 but not greater elasticity." He is not, however, correct when he states that though there is a greater density near the body, there is not a greater elasticity, as such an assumption is opposed to experiment and observation in relation to perfect gases, as I shall show when dealing with the elasticity of the Aether.

Again, in view of the fact that the Aether is atomic, it can now be easily understood how it may be subject to Gravitation. The very essence of Gravitation is that atoms, or particles, attract each other. If there were no particles, or atoms, it is obvious that there would be no attraction, and therefore no Gravitation. Wherever, therefore, there are to be found atoms of any kind or sort, whether they be atoms of hydrogen, oxygen, silver or aetherial atoms, there the Law of Gravitation holds good, and attraction between these atoms is to be found. In other words, any substance which is atomic, is also gravitative. Now Aether is atomic as has been shown, and therefore from that standpoint it is also gravitative. It may, however, be objected that the assumption of gravitative properties for the Aether is after all but a speculation, and that Young's fourth hypothesis was only a hypothesis, and that the gravitating properties of the aetherial medium have never come within the scope of direct experiment, without which no hypothesis can be fully accepted.

If such an argument be advanced against a gravitating Aether, then I must differ from those scientists who advance such an objection. My contention is that the gravitating properties of the Aether have already been made the subject of some of the most refined and delicate experiments that have been made during the past few years.

I refer to the experiments of Michelson and Morley of America.

For an outline and explanation of such experiments I must refer the reader to the _Phil. Mag._ of December 1887.

Now what is the result of these experiments?

I believe it is almost unanimously conceded by all scientists, that their experiments prove that the Aether is carried along by the earth. Let us carefully look at this conclusion and see what it implies in relation to the question at issue.

If the Aether is carried along by the earth, it necessarily follows that there is some governing law or principle which holds it to the earth, while the earth moves through space with its velocity of 68,000 miles per hour.

Now what is that governing principle or law, which is capable of holding such an aetherial atmosphere to its central body? If we wish to be strictly philosophical, it is necessary, according to our second Rule of Philosophy, that we should not go outside experience and the analogy of Nature.

Where is there a similar analogy in Nature to that of the Aether being carried along through space by the earth? I know of only one analogy which can be used, and that is the analogy of the atmosphere, which is also carried along by the earth through space, as it rushes on in its orbit round the sun.

That being so, the question arises, what principle or law holds the atmosphere to the earth? for, whatever be the law which governs the atmosphere, to be consistent with the second Rule of Philosophy, we must infer that the same law also holds the Aether in its place. There is only one answer to the latter question, and that is the Law of Gravitation. If it were not for that law, and the fact that the atmosphere is subject to that law, the atmosphere would simply be swept off from its central body, the earth, as the latter rushed through space with its comparatively enormous velocity.

The only legitimate and philosophical conclusion that we can arrive at, therefore, is that the Aether must be carried along with its central body, the earth, through being acted upon by the self-same Law of Gravitation, and for it to be so acted upon it must obviously be gravitative. It would be unphilosophical to suggest that it was held in its place by any other force, as that would be introducing a new force or law into Nature, contrary to our experience in relation to an exactly similar phenomenon of Nature.

We have therefore, it seems to me, direct proof by actual experiment that Young's fourth hypothesis was correct, and that not only in relation to the atomic world, but also in relation to the planetary world, and the stellar world, all bodies exert an attractive influence upon the surrounding Aether, by means of which the Aether is accumulated near the surfaces of all bodies in a state of greater density, and therefore of greater elasticity.

Let us apply this truth to the solar system, and see what we get. If it is true that the earth exerts an attractive influence upon the surrounding Aether by means of which it is held in its place relatively to the earth, then it is equally true that Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune also exert gravitating or attractive influences upon the surrounding Aether, in the same way that they do upon their own atmospheres. So that in their cases also, the surrounding Aether is carried along by them through space. Professor Stokes has suggested that this is so, in order to account for the aberration of light, as we shall see later on.

Not only so, but the sun also would have an attractive power over the Aether by means of which its aetherial atmosphere would be carried through space, as it moved along in its progress at an estimated rate of 17,000 or 18,000 miles per hour.

I would like to point out here, that this explanation of the effect of the planets' attractive power over the surrounding Aether is only a partial one, as there are other effects directly involved in the fact that the Aether is subject to the gravitating influence of all satellites and planets.

This is not the place, however, to go fuller into the matter, the consideration of the subject being taken up in a later chapter.

Thus I have tried to show a gravitating Aether is strictly in accord with the three Rules of Philosophy, for it is simple in conception, is not contrary to experience, and by it I premise that it is possible to explain the physical cause of Gravitation, with all that is involved in that law.

Once more, if Aether is gravitative, then every atom and particle in the universe, as well as every planet, and sun, and star, exert an attractive power over the Aether, so that every atom is enveloped in an atmosphere of Aether, in the same way that every planet, and sun, and star is enveloped by the aetherial atmosphere.

The Aether, however, while it may flow through the spaces that exist between the molecules of bodies, yet is held bound to those molecules in the same way, and by exactly the same force, that holds the atmosphere to a planet or world.

Further, if the atoms possess different masses or weights, as they do, then each atom would possess an aetherial atmosphere proportionate to its mass, with the result that an atom of carbon, with its atomic weight of 12, ought to possess a denser aetherial atmosphere than an atom of hydrogen, and so on right through the atomic scale. I need hardly point out that this conception of the Aether in relation to atoms, and molecules of bodies, will solve certain problems relating to the density of Aether in connection with matter, which problem up to the present cannot be solved by the present conception of a frictionless medium.

That problem may be stated as follows: Does the presence of matter affect the Aether in any way, so as to load or make it denser? Professor Lodge, in _Modern Views of Electricity_, in relation to the density of the Aether, writes: "The neighbourhood of gross matter seems to render Aether more dense. It is difficult to suppose that it can really condense an incompressible fluid, but it may load it, or otherwise modify it, so as to produce the effect of increased density."

In view of the fact that Aether is gravitative, the reply is to be found in the Law of Gravitation, "Every particle of matter attracts every other particle of matter, etc.," and as Aether is matter, it will be attracted by the other matter irrespective of whether that matter be in the atomic, molecular, or planetary or stellar form. We shall see that this is so when we come to deal with the density of the Aether.

It may be objected in relation to this aspect of Aether, that Young also asserted that the Aether flows as freely through matter, as the air flows through the trees of the forest, and that such a statement therefore contradicts his fourth proposition regarding the gravitating properties of Aether. A little reflection will, however, put a different construction on this objection.

Let us consider the analogy from the standpoint of experience, and see what that analogy teaches us. From experience we learn that the air is gravitative, but we also learn that it is possible to be moved from place to place as winds, and that as such it can move freely between the trees of the forest, causing their boughs and leaves to tremble and bend beneath its energy and power.

I have yet to learn, however, that while it moves between the trees as separate and distinct objects, such a movement militates or destroys its gravitating properties.

Does the air cease to be any less gravitative, or subject to the Law of Gravity, when it is subject to certain movements, which give rise to certain currents as winds? Such an assumption is altogether opposed to philosophical reasoning.

Whether the air is stationary or in motion, it is ever subject to the great Law of Gravitation, and accepting that as an analogy, the apparent contradiction between the oft-quoted simile of Young and his fourth hypothesis is at once removed, and from analogy we learn that it is quite possible for Aether to move between bodies because of certain currents which may be originated by heat, light or electricity, yet at the same time the existence of such currents does not violate its gravitating tendency.

Young's fourth hypothesis is therefore in perfect harmony with his oft-quoted simile, that the Aether flows through the interstices of bodies as the wind flows through a group of trees, but like the air-currents it does not so flow unless the currents are generated by some form of energy, as heat or light, electricity or magnetism.

From these considerations therefore we are compelled to come to the conclusion that Aether, like all other matter, is subject to the same universal Law of Gravitation. If further evidence of the gravitating tendency of the Aether were required, I would refer the reader to Lord Kelvin's utterance on this subject.

Lord Kelvin, _Phil. Mag._, November 1899, in relation to the Aether writes: "We are accustomed to call Aether imponderable. How do we know that it is imponderable? If we had never dealt with air except by our senses, air would be imponderable to us, but we know by experiment that a vacuum glass tube shows an increased weight when air is allowed to flow into it. We have not the slightest reason to believe that Aether is imponderable. It is just as likely to be attracted by the sun as air is. At all events the _onus of proof rests with those who assert it is imponderable_. I think we shall have to modify our ideas of what Gravitation is, if we have a mass spreading through space with mutual attraction between its parts, without being attracted by other bodies."

We have already seen in the previous article that Faraday was of opinion that the Law of Gravitation extended throughout the whole of the solar system, and as Aether fills the solar system, then obviously Aether must also be subject to the Law of Gravitation.

ART. 46. _Aether possesses Density._--That matter possesses density has already been shown in Art. 38, and on the hypothesis that Aether is matter, Aether must possess density also. This property has already been postulated for the Aether, in order to account for certain phenomena in connection with the reflection and refraction of light. Young assumed different densities for the Aether near bodies owing to its being attracted by those bodies (Art. 45). Reflection and refraction of light are produced by a change of density of the Aether. It is now generally accepted that the optical difference of bodies depends mainly on the different densities of Aether in association with those bodies. Professor Tyndall, in his _Lectures on Light_, writes on the density of the Aether as follows: "The density of the Aether is greater in liquids and solids than in gases, and greater in gases than in vacuo. A compressing force seems to be exerted on the Aether by the molecules of these bodies."

Apart, however, from the atomicity and gravitative properties of the Aether, it is difficult to understand how there can be density of the medium, and still more difficult to give a satisfactory explanation of different degrees of density for the same medium, which some scientists assume it to have.

If, however, all that is logically included in the statement that Aether is matter, and therefore is atomic and gravitative, is conceded, then, from the analogy of our own atmosphere in relation to the earth, the density of the Aether, and different degrees of density also, is at once put upon a logical and philosophical basis, as it is brought into harmony with all experience and observation, and is simple in its conception.

On the other hand, an Aether which is not atomic or gravitative cannot possess different degrees of density, except by assuming the existence of some unknown law of which we have no knowledge, which conception is altogether opposed to the fundamental principles of simplicity, observation, and experiment as laid down not only by Newton but by every true philosopher.

Therefore, that Aether can possess different degrees of density, is only the logical outcome of the statement that Aether is matter, seeing that such a statement without the shadow of a doubt must at least imply that it is gravitative.

I need hardly point out, that it is much more philosophical to be able to account for the density of the Aether in a reasonable and philosophical manner, than simply to postulate for the Aether certain properties and qualities, because certain phenomena demand the existence of such properties.

The Aether has been such a hypothetical medium, that it has been easy to postulate for it certain properties, if certain phenomena have demanded the existence of those properties.

Thus if the Aether were required to be elastic, then elasticity was postulated for it; if more elastic, then greater elasticity was added. If density were demanded, then density was postulated, and if less or more density, less or more density was given to it.

That method of speculation may be satisfactory up to a certain point, but no one will admit that such a method is wholly philosophical. It will be a far better method to adopt, if, in dealing with the universal Aether, we can make it conform to certain recognized laws and principles, and from the application of those well-known laws, be able to infer the exact constitution of this space-filling Aether medium.

Now the question arises, if Aether is gravitative, what effect has the Gravitation of any body, be it an atom, or a meteor or planet, sun or star, upon the Aether in which it moves, and which surrounds it?

That we may have some light thrown upon the matter, I would like now to take the reader to Newton's _Optics_, in order that he may give us his opinion as to this property of density of the Aether. In his nineteenth query Newton (_Optics_) asks this question--

"Is not this medium much rarer within the dense bodies of the sun, stars, planets and comets than in the empty spaces between them, and in passing from them to great distances, doth it not grow denser and denser perpetually, and thereby cause the gravity of those great bodies towards one another, and of their part towards the bodies, every body endeavouring to go from the denser parts of the medium towards the rarer?"