Earlier Theories of
Gravity

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Earlier Theories
of Gravity  (1913)
by Hereward Carrington

The Monist, 1913,
23: 445-458, Online

Earlier Theories of Gravity Hereward Carrington

1913

It is universally conceded that gravitation is the most incomprehensible of
all forces. Gravitation is supposed to be included in the law of conservation of
energy, and from one point of view there is doubtless evidence to show this.
When a body is poised upon the edge of a table, let us say, it possesses a
certain amount of potential energy. When that body falls to the ground, its
potential is converted into actual or kinetic energy. The energy is therefore
released from the body which now possesses none. The energy it once possessed
has been expended and converted into the work of the world, or its energy has
been radiated uselessly into space; and thus we see how gravitation, the
attraction of the earth for all material bodies, can be made to enter into the
circle of generally recognized forces and included in the law of conservation.
It might be questioned whether potential energy is energy in the strictest sense
of the term, but I shall let that pass for the moment and assume that these
facts prove what they are said to prove.

Gravitation is certainly the most mysterious of all known forces, and even
yet nothing definite can be said as to its modus operandi. In the case of all
other forces known to us it is possible to shut off their influence, to find
some body which is opaque to their power. Take, for instance, light and
electricity. Roughly speaking, glass permits the passage through it of light
rays but prevents the passage of electric rays. Steel on the contrary, being a
good conductor, permits the passage through it of the electric current but is
impervious to light. The same is true of all other forces with the single
exception of gravitation. No body has been found opaque to gravitation. It seems
to exert its influence above, below, and equally upon all sides of any object.
The introduction of a solid sheet of metal, of glass, or of any substance
whatever, seems to have no appreciable effect. The body beneath which it is
introduced seems to be attracted to the earth by gravitation just as strongly as
it was before the introduction of such a sheet. And yet, from all that we know
of force and energy, such should not be the case! We are [446] confronted by an
insoluble mystery. What is the nature of this force? How can it be conceived to
act? What speculations have been advanced by men in the past to account for this
mysterious phenomenon which has so puzzled the world since Newton's first famous
experiments?

It is interesting to note that Newton himself speculated on this subject, and
some years before arriving at his great generalization he threw out a suggestion
as to the cause of terrestrial gravity in a letter to Boyle. In view of the
recent experiments performed by the Cambridge school in England, by Dr. Gustav
Le Bon and others in France, and by various other scientists — demonstrating
apparently, that matter is resolvable into ether, or a mode of energy within the
ether — the following extract from his letter shows remarkable foresight upon
his part and deserves preservation. Writing in January 1678, Newton thus
unfolded his hypothesis:

"First, it is to be supposed that there is an etherial medium, much of the
same constitution as air, but far rarer, subtler, and more strongly elastic, but
it is not to be supposed that this medium is of one uniform matter, but composed
partly of the main phlegmatic body of the ether, partly of other various
etherial spirits, much after the manner that air is compounded of the phlegmatic
body of air, intermixed with various vapors and exhalations; for the electric
and magnetic effluvia, and the gravitating principle seem to argue such variety.
Perhaps the whole frame of nature may be nothing but various contextures of some
certain etherial spirits or vapors, condensed as it were by precipitation, much
after the manner that vapors are condensed into water. . . .Thus, perhaps, may
all things be originated from ether."

Newton's own theory of gravitation he formulated thus:

"I will suppose ether to consist of parts differing from one another in
subtlety of indefinite degrees, in such a manner that from the top of the air to
the surface of the earth, and again from the surface of the earth to the center
thereof, the ether is insensibly finer and finer. Imagine now any body suspended
in the air, or lying on the earth, and the ether, being by the hypothesis
grosser in the pores which are in the upper parts of the body than in those
which are in the lower parts, and that grosser ether being less apt to be lodged
in those pores than the finer ether below, it will endeavor to get out, and give
way to the finer ether below, which cannot be, without the bodies descending to
make room above for it to go into. . . .From this supposed gradual subtlety of
the parts of the [447] ether, some things above might be further illustrated and
made more intelligible."

It is well to bear in mind that every hypothesis which attempts to explain
gravity is required in limine to give a satisfactory account of the following
six characteristics of this mysterious influence:

1. Its direction is radical toward the acting mass, or rectilinear —
indefinitely. This rectilinear traction is incapable of deflection by any
intermediate force. It suffers neither disturbance nor interference from any
multiplication of similar lines of action, and admits neither of reflection,
refraction, nor of composition.

2. Its quantity is exactly proportional to the acting mass —
indefinitely.

Corollary: Hence its integrity of action is complete with every
accumulation of additional demand — indefinitely ; this is to say, no
multiplication of duty in the slightest degree impairs its previous
tensions.

3. Its intensity is diminished by recession, in proportion to the square of
the distance through which it acts — indefinitely ; in a manner somewhat
analogous to — but (as modified by the second condition) radically different
from — the action of light.

4. Its time of action is instantaneous throughout all ascertained distances,
and therefore, presumably, — indefinitely.

Corollary: Hence its rate of action, (if the expression may be
tolerated) is precisely the same on bodies at all velocities — indefinitely. It
no more lags on a comet approaching the sun at the speed of two hundred miles or
more per second than on a body at the lowest rate of motion, or than on the same
comet receding from the sun at the same velocity.

5. Its quality is invariable under all circumstances — indefinitely. It is
entirely unaffected by the interposition of any material screen, whatever its
character or extent ; or, in other words, it can neither be checked by an
insulator nor retarded by any obstruction.

6. Its energy is unchangeable in time, certainly for the past two thousand
years ; presumably — indefinitely.

Corollary: Hence, its activity is incessant and inexhaustible —
indefinitely; the ceaseless fall of planets from their tangential impulses
involving no dynamic expenditure in the sun or in other known matter.

Let us now give a rapid summary of the theories that have been advanced from
time to time to explain this mysterious force. Arago, in his Popular Astronomy,
attempted to show that gravitation traveled [448] with fifty million times the
velocity of light, and that the time required to reach us from the nearest star
would be about two seconds. Philippe Villemot, a French doctor of theology and a
distinguished mathematician, advanced a theory in 1707 that gravitation is
occasioned by a difference of pressure on the outer and inner faces of the fluid
constituting the solar vortex, owing to an increase of its density outward from
the sun. The general conception is obviously somewhat similar to Newton's
speculation hazarded in 1678. The next attempt at a solution was offered by
Bernoulli, of Switzerland, who attempted to show that gravitation of the planets
toward the center of the sun, and the weight of bodies towards the center of the
earth, were caused by the immediate impulsion of a substance which he termed
"the central torrent." This was continually thrown from the whole circumference
of the vortex to its center, and consequently impressions on all bodies
encountered by it in its path imparted to them the same tendency towards the
center of the vortex.

Lesage,
in 1750, was the next philosopher to advance a definite theory of gravitation.
To quote Arago's exposition of the theory, it was as follows :

"A single body placed in the midst of such an ocean of moving corpuscles
would remain at rest, since it would be equally impelled in every direction. On
the other hand, two bodies ought to advance towards each other since they would
form a mutual screen, as their opposed surfaces would no longer be hit by the
ultra-mundane corpuscles in the direction of the line joining them, and there
would then exist currents whose effect would no longer be neutralized by
opposite currents. Moreover, it will readily be seen that two bodies plunged
into such a "gravitation fluid" would tend to approach each other with a force
varying inversely as the square of the distance."

While this theory finds some support from facts known to science, and has
even been called "the only plausible answer to this great problem which has yet
been propounded," yet the theory utterly fails to account for many of the known
facts, and seems to be in contradiction to others. All that can be said for it
is that, unlike most other theories of gravitation, it is at least conceivable
and has some faint beginnings of scientific precision.

Leonard Euler, a Swiss mathematician and philosopher, published in 1760 a
treatise in which he commented on the action of gravitation as
follows :

"Supposing a hole made in the earth through its center; it is [449] clear
that a body at the very center must entirely lose its gravity, as it could no
longer move in any direction whatever, all gravity tending continually toward
the center of the earth. Since then a body has no longer gravity at the center
of the earth, it will follow that in descending to this center its gravity would
have gradually diminished ; and we accordingly conclude that a body,
penetrating into the bowels of the earth, loses its gravity in proportion as it
approaches the center. It is evident, then, that neither the intensity nor the
direction of gravity is a consequence from the nature of any body, as not only
its intensity is variable but likewise its direction, which on passing to the
antipodes becomes quite contrary."

Herapath next, in 1816, published an essay "On the Physical Properties of
Gases." He attempted to show that there was "one cause for heat, light,
gravitation, electricity, cohesion, aerial repulsion, etc., from which all these
flow, and are deducible ; and their effects may be computed by mathematical
induction [deduction?]. It shows us that gravitation, cohesion, and affinity are
but the same thing under different modifications ; that the differences of
the two latter arise from a difference in the figures and sizes only of the
particles ; that attraction and repulsion are not properties of
matter."

Herapath contended that, by noting the continued and mutual condition of
particles of gases in the containing vessels, and by extending the principle to
the planets, which he supposed to be all of the same density as the earth, he
attempted to show that it was possible to calculate the amount of gravity of
varied bodies, one toward another. There were of course several fundamental
defects in his theory- so obvious that they need hardly be mentioned. The known
dissimilarity of the composition of stellar bodies, and the fallacy that any
pressure-differences would result from temperature- differences, naturally
vitiated his whole argument.

The next ingenious attack upon the problem was made by Guyot in 1861 in an
essay entitled "A Sympathetic Glance at the Form and Forces of Matter." Still
maintaining that all the properties of bodies are derivatives of their vibratory
movements, and that the equilibrium and the phenomena of the world exist only
under the condition of constant pressure of the ether upon coercible matter and
the reaction of the latter upon the former, he argues that "if it be shown that
the vibration of the atoms of bodies may and actually does cause the rarefaction
in the sphere of activity of each of the atoms," this constitutes a proof that
"the approximation of the atoms of bodies of ponderable matter is due to the
rarefaction [450] of the imponderable fluid, and consequently to the diminution
of its pressure in the space between the atoms of the same body" ; and
hence that "we are compelled to admit that attraction is a mechanical force,
consisting first of the rarefaction of the ether between molecules, masses, or
the heavenly bodies, resulting from the ceaseless vibration of the atoms of
ponderable matter ; and secondly of the reaction from the exterior pressure
of the ether upon the same, resulting from the general pressure of the
imponderable universal medium which constitutes the mother-liquor of the
world."

In 1844 Faraday issued a speculation on the nature of matter in which his
first unformed views were stated. This was followed in 1850 by a memoir on the
possible relation of gravity to electricity, in which he stated his belief that
there was such a definite connection, though he could give no proof of it.
Several years later in a memoir on "The Conservation of Force" he gave the
results of his further meditations on "the attractive theme of gravitation."
They were these:

"It is a simple attractive force, exerted between any two or all the
particles or masses of matter at every sensible distance, but with a strength
bearing inversely as the square of the distance. . . . For my own part, many
considerations urge my mind toward the idea of a cause of gravity which is not
resident in the particles of matter, merely, but constantly in them and all
space. I would much rather incline to believe that bodies affecting each other
by gravitation act by lines of force of definite amount or by an ether pervading
all parts of space, than admit that the conservation of force could be dispensed
with."

On no subject, perhaps, have the distinguished author's ideas been more vague
and intangible than on this.

The next speculations of note are those by Seguin, submitted to the French
Academy of Sciences in 1848 and 1858. In his earlier writings he held to a crude
kinetic theory, founded upon the laws of cohesion, repulsion, attraction, etc.
In 1858, however, Seguin published in the Cosmos a somewhat elaborate essay on
the origin and propagation of force, in which he seems to have abandoned the
kinetic theory of gravitation. It is true that he there holds that " matter is
inert ; that is to say it does not harbor in itself the power to put itself
into movement, and still less, a fortiori, to communicate it, since a thing to
be transmitted must first exist." And it is also true that he repeatedly speaks
of "the great principle of infinite conservation of motion" as being the
foundation of all mechanics, [451] and regards the possibility of destruction of
motion as equivalent to annihilation of force.

Notwithstanding all this, he says in regard to the uniform tendency of a
material system towards its center of gravity :

"We are thus led to consider attraction as a first cause, emanating directly
from the Divine Will in the creation of matter. Doubtless, it is not impossible
that it may hereafter be discovered that attraction in its turn is only a
consequence of a more general law, comprehending in itself more implicitly the
means of explaining the effects attributed to attraction .... But as these
considerations are purely metaphysical since observation cannot reach beyond the
established fact that two confronting bodies gravitate toward each other by
virtue of a force to which is given the name of 'attraction,' it appears to me
wiser not to advance further to penetrate a mystery which nothing within our
knowledge as yet appears able to explain. Let us then consider matter as
existing from the beginning, uniformly in space, and attraction as an essential
property with which it is endowed, by virtue of which the different parts or
molecules composing it possess in themselves the power of mutual
attraction."

M. de Boucheporn read a memoir to the French Academy of Sciences, July 30,
1849, in which he attempted to explain the general laws of gravitation. It was
based on the idea that the movements of the heavenly bodies might be explained
by an external impulsion, or by the action of a universal fluid. He pointed out
first, that the intensity of the impulse propagated in the etherial medium
follows the law of the inverse square of the distance from the center of
disturbance ; second, that the resistance of the ether does not sensibly
effect the velocity of a body when this is sufficiently less than that of the
theory of propagation ; third, that taking the density of the fluid as
unity, the quantity of motion impressed by a body on the ether is equal to its
volume multiplied by the square of its velocity ; fourth, that the pressure
would produce the effect that all layers of equal thickness would include the
same quantity of matter if propagated to the interior of the heavenly bodies,
and that the mean density is three times that of the surface ; "fifth, as
to attraction, the displacement of the ether by the movement of a body, A, will
produce in all parts of the fluid a sort of aspiration toward the point being
left by its center ; and any body, B, receiving these aspiring waves on its
nearer hemisphere, will have lost all or a part of its own pressure, and the
half pressure (volume multiplied by the square velocity) which acts on the
opposite hemisphere, no [452] longer being counterbalanced, will give an impulse
to the body B, in the direction of A. Such would be the principle of
attraction."

In a learned work on elasticity, Gabriel Lame, in 1852, next attacked the
problem of gravitation. He insisted on the necessity for admitting an
all-pervading ether. Having theoretically proved its existence, he contends that
it is scarcely to be doubted that in the intervention of the ether is to be
found the secret or true cause of the effects which are attributed to heat, to
electricity, to magnetism, to universal attraction, to cohesion, to chemical
affinities. For all these mysterious and incomprehensible agencies are at bottom
but coordinating hypotheses.

In 1858 J. J. Waterston, of Edinburg, published an essay entitled " On the
Integral of Gravitation, and its Consequence with Reference to the Measure and
Transfer or Communication of Force." He contended that "a force-generating
faculty exists in space and is directed centripetally. The mutual gravitation of
two bodies," he said, "develops mechanical force in each of them, inversely
proportioned to its mass." The theory is really very indefinite throughout,
since he appears to make gravitation a function of space, being the content of
space, or the dynamic medium supposed to occupy it. It may be said that his
speculations have failed to find corroboration.

Prof. James Challis, in 1859, published a series of communications beginning
with his mathematical theory of attractive forces, and following it through in
other papers on "Force," and "Gravitation." He found the theories of elasticity,
cohesion, attraction and repulsion in matter insufficient to account for the
facts, and was forced back upon the ether. "Yet," he says, rightly enough, "as
it is contrary to principle to ascribe elasticity to atomic matter, the question
might arise, why is it more proper to ascribe this occult property to the
ether?" Concluding that we cannot, he stated his conviction that "we must
conceive another form of ether, having the same relation to the first as that
has to air." In 1876 this author returned to a discussion of the problem. In
dealing with the residual effect of vibration, which, he said, "is the
attraction of gravity," he says:

"This result expresses the force of gravity as due to the attractive action
of a molecule of a higher order as to magnitude than the molecule of molecular
attraction. For distinction, a molecule of this superior order might be called a
gravity-molecule. Its magnitude may still be considered to be so small that in
comparison with [453] the magnitudes of terrestrial and cosmical masses, it may
be treated as an infinitesimal quantity .... Lastly, it is to be noted that on
account of the large value of X for gravity-waves they do not suffer sensible
retardation or refraction in passing through gross bodies. I have on several
previous occasions treated of the problem of gravitating force theoretically,
and by slow steps have approximated to its solution ; but before the
present attempt I had not succeeded in exhibiting satisfactorily the rationale
of this kind of attraction by vibrations."

In 1861, Mr. J. S. Glennie published in The Philosophical Magazine several
papers on the subject of gravitation. Summarizing his own views in later
articles, Mr. Glennie thus recapitulates and states the substance of his
theory:

"Matter is conceived to be made up, not of an elastic ether and inelastic
atoms, but of elastic molecules of different orders as to size and density. If a
rough physical conception of these molecules be required, they may be conceived
as etherial nuclei, the ether of the nuclei of a lower, being made up of nuclei
of a higher, order, and so on ad infinitum."

Mr. Glennie postulated a universal repulsion, varying through various
intensities, instead of universal attraction; but, could it be discussed in
detail, it must be said that his theory completely fails to be convincing.

Keller in 1863, Tait in 1864, and Saigey in 1866, all offered speculations
upon this subject, based more or less on their theory of force. Saigey went so
far as to say that bodies do not owe their gravity to an intrinsic force, but to
the pressure of the medium in which they are immersed. Why this pressure should
vary at various points in the universe is not stated.

In a communication to The Philosophical Magazine in 1867, Mr. James Croll
revived the difficulties that had been stated by Faraday and attempted to solve
them. He was first of all led to the conclusion that there must be, in order to
account for the facts, a destruction of force in one place and a creation of
force in another. Finding, however, that this ran counter to the law of
conservation of energy, he gave up that attempt and attacked the problem in a
different direction. Discussing it from the point of view of the law of
conservation of energy, he pointed out that if gravity be correlated to other
forms of energy, it must be included in the law of conservation. But here he was
met with difficulties. Admitting that gravity can perform mechanical work, and
mechanical work can [454] be converted into other forms of energy, he yet
pointed out that it is generally denied that there is a decrease or loss of
gravity resulting from such transformations, that is, the body did work without
losing any of its force of gravity. It would therefore appear to be outside the
law of conservation. After much theoretical discussion, Mr. Croll arrived at the
following conclusion : That gravity is in all probability of the nature of
an impact or pressure. Finding he could not account for it either on the theory
that it resulted from the impact of corpuscles or from the difference in
pressure of a substance filling space, he was forced to the conclusion that it
was some kind of "pure force."

In 1869, P. Leray published an essay entitled "A New Theory of Gravitation."
In this he postulated first, the existence of an ether ; second, that at
every point there exist equal currents crossing each other in all
directions ; third, that in passing through bodies the currents of the
ether are retarded proportionately to the thickness traversed and to the mean
density of the path. In the same year Boisbaudran published a short paper
entitled "A Note on the Theory of Weight." His conclusion was: "It is to the
longitudinal vibrations of the ether that I attribute the cause of weight."
Guthrie in 1870 published an account of some experiments entitled, "On Approach
Caused by Vibration." His hypothesis practically made gravitation a function of
temperature, which was of course, contrary to all observation.

Sir William Crookes in 1873 offered some speculations in which he pointed out
the possible influence of the energy of light-waves as effecting the results,
but his statements at that time were little more than restatements of the
difficulties, and he had no positive theory of his own to offer.

Lord Kelvin, in his essay "On Ether and Gravitational Matter Through Infinite
Space," in 1901 said : "The potential energy of gravitation may be in
reality the ultimate created antecedent of all the motion, heat, and light at
present in the universe." It will be observed that his definition is really
vague and does not attempt to tell us what the kinetic energy of gravitation may
be. Speculations have also been advanced on this subject by the Cambridge
school, by Sir Oliver Lodge, Dr. Gustav Le Bon, and others. It is hardly
necessary to say, however, that their articles have consisted almost entirely of
accounts of the difficulties to be faced by any theory advanced, and but little
has been offered by way of positive theory.

It may be said that the newer discoveries in physics have had [455] a double
bearing upon this problem. The experiments carried on of late years may,
perhaps, have furnished us with the first outlines of a possible
reconstruction ; a comprehension of the facts. On the other hand, they have
made the phenomena more mysterious than ever! Gravity has no appreciable action
on electricity, while it is the sole reason of the laws governing the flow of
liquids. Nevertheless, it more nearly resembles electricity than any force we
know. As Dr. Le Bon said in his Evolution of Forces: "One gets clearer and
clearer glimpses that weight is due to the relations between the ether and
matter, connected, doubtless, by lines of force ; but this is only a more
or less vague hint, which still escapes the teachings of experiment. It is
possible that the gyratory movement of the atoms are communicated to the ether
and through it to the different material bodies, thereby establishing an
attraction between them. The reciprocal attraction of vortices has, at the
present day, been demonstrated by many experiments. . . .Gravitation displays
the incomprehensible characteristic, which no other manifestation of energy
possesses, of not being arrested by any obstacle. The most delicate researches
have shown that no body exists which is opaque to gravitation. Gravitation is a
very small force if we consider only the action of the masses we have at our
disposal, but it is a force extremely great for considerable masses. This power
is apparent to us every day in the phenomenon of the tides. Under the influence
of the combined motion of the sun and moon, the seas are raised to an average
height of one meter, which represents a weight of one thousand kilogrammes per
surface-meter.

"Physicists have been able to say nothing more on gravitation than what is
said above. In an important memoir of which I reproduce a few passages, Prof.
Vernon Boys has shown perfectly how inexplicable it remains. 'It seems to defy,'
he says, 'all our attempts to abandon the inconceivable idea of action at a
distance ; for even when we might conceive another mode of action it is
entirely incomprehensible that gravitation should act at a distance without
regard to the existence or nature of bodies in its path, and, as it appears,
instantaneously .... The speed of the propagation of gravitation was estimated
by Laplace as being immensely higher than that of light. Henri Poincare
considered it as propagated with a velocity of the order of that of light
vibration. We do not know how gravitation is propagated, but it seems to me that
the law of the inverse square of the distance allows us to imagine gravitic
waves having a form analogous to that of the waves of light, electric [456]
waves, etc When a force decreases with the distance in accordance with this law,
it is legitimate enough to imagine that it is propagated by spherical waves.
This should be the case with gravitation."

So long ago as 1876, Mr. William B. Taylor, in his valuable essay on
gravitation, pointed out the difficulties in the various theories that had
been advanced by way of explanation. The corpuscular theory, even in his time,
he regarded as finally and conclusively disproved. The hypothesis of undulations
he regarded as equally impossible. He pointed out that such undulations as had
thus far been established were quite incapable of inducing anything in the
slightest degree analogous to gravitation, and that the new species of
undulation necessary for the theory have never been proved. Great as is the
credit due to Professor Challis, for instance, for his laborious efforts to
develop this theory by the stern logic of mathematics, the whole demonstration
is vitiated by the unwarranted preliminary assumption of qualities and modes of
action in the ether analogous to those of gases ; but experiment has failed
to demonstrate any such similarity. Even if the undulation postulated were
proved it would be entirely inadequate to account for the facts. The experiments
of Guyot and Guthrie quite conclusively show that neither in the law of quantity
nor in the law of intensity can gaseous vibrations represent even approximately
the ascertained facts of gravitation embodied in the general propositions. The
difficulties presented by inertia, elasticity, etc., have likewise never been
overcome.

Failing thus at every point, the hypothesis leaves still more inscrutable the
origin of the undulation. The center of disturbance is supposed to be the
vibrating material element ; but the cause of the vibration is never
stated. If "innate tendency" be the answer, never surely was a more mysterious
"occult quality" attributed to matter in the history of physics. Force cannot
originate without an originator. The new discoveries in physics have thrown an
entirely different light over this problem, causing us to reconstruct our views
as to the nature of matter and energy, and their interrelation. Matter, in fact,
has been resolved into energy and springs from it. We have the universe traced
back to a homogeneous primal ether in rest. Once this ether receives an initial
impulse, then all the rest would follow — etherial vibrations, electric atoms,
material atoms, worlds, the universe ! And into ether all shall
return ! What caused that prime initial impulse? That we cannot say.
Science says that " forces unknown to us" caused it to emerge. It is possible to
conceive [457] that this first grand impulse was none other than some human or
divine Will.

Nevertheless, granting a prime mover— the immediate operation of a demiurgus,
if necessary — the difficulty would still remain : How is the initial
impulse converted into vibration? What is the resisting power deflecting the
element in motion from that rectilinear direction which is the first law of
action? Upon that subject there is a very remarkable reticence. Is the universe
a perpetual motion machine?

There is no reason whatever to believe that the ether is a source of energy.
We have no experience of any undulations originating in its broad expanse. It is
never self-luminous ; and even in the case of electricity there is always
required the disturbance of a material element. Nor it there any ascertained
fact to warrant the supposition that the ether is a reservoir of force, in any
other sense than that, without the possession of intrinsic tension, it would be
incapable of transmitting energy (I am using the terms "matter" and " force"
here as they are commonly understood). There is a great deal of loose
speculation current regarding the nature of this supposed ether. Dr. A.
Rabagliati, in his introduction to my Vitality, Fasting and Nutrition, called
attention to this, and said : "But what is this ether? M. Le Bon tells us,
or at least suggests to us, that it is a solid without density or weight. Some
scientists indeed suggest to us that the ether has density and no weight, while
others say that it has weight and no density ! These are the men, be it
observed, who speak somewhat disparagingly of 'purely metaphysical
considerations.' They deduce their conclusions from 'experiments.' But are not
the definitions purely metaphysical? And are they any less so because deduced
from experiments? It is a highly interesting state of mind which uses
metaphysical expressions, and justifies them because they are alleged to have
been come to by 'experiments' and not from philosophical considerations. A solid
without density or weight ! What is such a body ? Is it nothing ?
I suggest that it is — nothing. But according to the thesis, it is the origin,
and it is again the grave of the atom. The atom then came from — nothing, and it
goes back to — nothing. But is not this the very proposition which, when it has
been stated by philosophic or religious men, has been sneered at by the
scientists? It is the very proposition ! But then it was made for
metaphysical speculation, and now that it has been stated from physical
speculation (is that it?) or from experimentists, it is allowable! Nay we must
yield [458] our consent to it. All I can say is, that never have I been asked to
believe anything more transcending reason by any philosopher. The scientific men
and the physicists and the experimentalists seem, certainly, to have got
themselves into a quagmire regarding this solid without density or weight, and I
wish them well out of it."

Thus the nature of ether cannot be said to be much more clearly defined than
that of gravitation. Both remain unsolved mysteries, closely related to one
another, and present many similar difficulties. Perhaps some "metaphysical
Newton" will one day solve the problem!

This
work is in the public domain in
the United States because it was published before January 1, 1923.

The author died in 1958, so this work is also in the public
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