# Popular Science Monthly/Volume 22/April 1883/Speculations on the Nature of Matter

 SPECULATIONS ON THE NATURE OF MATTER.[1]
By HENRY HOBART BATES, M. A.

THE nature of matter is still almost as unknown to us in its essence as it was to the ancients, since in its minute structure it lies far below the range of the senses, or of instrumental appliances, and, therefore, beyond that direct experimental field so necessary in furnishing primary conceptions to the mind. From the impossibility of originating entirely novel ideas (which would amount to creative power), we are forced to combine and recombine such conceptions as we have, derived from experiences within that excessively small portion of the scale of being within the ken of our perceptions and faculties. This perceptible scale has been somewhat extended in both directions by refined modern instrumental means, and thus the number of elementary concepts has been slightly increased, while precision has been added to those already in possession, by stricter modes of analysis.

The field, however, is still largely speculative. It might, therefore, seem unprofitable and unscientific to labor in it, were it not for the urgent necessity for and great value of some working hypothesis, however crude (if on the road to truth), as an aid and stimulus to further progress. Without hypothesis, we can not interpret or collocate such facts as we gain; while, without facts, we can not improve our hypothesis.

The great trouble about matter is to find out how much of it and what in it is material. Strange to say, there is nothing on which philosophers are less agreed. Unfortunately, our notions of matter are derived solely from sense impressions; and that form of it which most impresses the senses is the most encumbered with fugitive and non-essential properties. We can not say with certainty whether these properties are positive or negative.

When upon a clear summer's day we gaze outward into a cloudless sky, we look apparently into clear and void space, except for the deep blue diffused light. We recognize vacuity. Even while we gaze, perhaps a light, fleecy cloud forms itself before our eyes, and we form the concept of the creation of a material object. We know that it is not a mere apparition—it is a form of substance. Properties begin to be recognizable in it. It reflects light—it displays color—it moves. Should its development progress, we shall have still further evidence of its substantiality. It will grow darker and more dense. It will exhibit gravity, and descend in liquid drops or solid flakes, and these portions in turn will exhibit the typical properties, qualities, and reactions of matter.

Now, what elicited this bundle of realities out of apparent nothing? A mere local refrigeration—a flaw of nothing tangible—abstracted something from the invisible potential occupant of the space, reduced its volume, sapped its mobility, its power of holding its own, and properties began to appear. Death began its work, and, as the animus fled, the skeleton framework came within our ken.

We might rise by analogy from the nimbus to the nebula—from the terrestrial to the cosmical—and see with imagination's eye a similar inverse evolution producing the apparition of things substantial, which may be really but the intaglio of the realities. For that which consists merely in the negation of something can not be the truest substance. An ulcer is not more material or real than the healthy tissue before the latter gives urgent call for recognition of its actuality by inflammation, incipient degradation, and advancing dissolution.

It may be possible, however, to corner a reality by the reverse process. A fair type of matter is our block of ice. It is sufficiently substantial, and loaded down with properties. A simple exposure to different temperature conditions causes its sensational properties to drop off like old clothes. We soon come to a pair of invisible and intangible existences, investigable by indirect means only, of which sufficient knowledge has been gained to establish their discontinuous or corpuscular character, as imagined by Democritus.

This molecule we must take as the representative of matter; for all masses of it, whether gaseous, liquid, or solid, are but aggregations of similar corpuscles. We can only pursue it with the eye of the imagination; for, as has been shown by the molecular physicists, its dimensions are so inconceivably minute as to far transcend the mechanism of vision, since it would require at least twenty thousand in a line to occupy a medium wave-length of light.

But could the molecule even be magnified to visible and tangible dimensions, with a new light to view it by, it could not by any means be rendered visible, either in whole or in its parts, on account of its incessant and marvelous activity, both interior and translatory. That the gas-molecule did not get its interior motion from the heat of dissociation is certain, for, on being allowed to recombine, it yields up its translatory activity, and with it as many degrees of temperature as disappeared in accomplishing the dissociation. No means of wholly destroying the interior motion are known. By some savants it is regarded as primordial and ultimate. It is highly probable, for reasons which Mr. Taylor has pointed out,[2] that the hydrogen-molecule contains at least four pairs of revolving elements, revolving in different periods, and in contractile orbits, but with periods as undeviating as those of the moons of Mars. It is in the revolving or vibratory constituent of this couple that we seek the final essence of matter, though perhaps not to arrive at it. We must not endow it with gratuitous attributes, but it is surely an entity of some kind, having, in the first place, persistent and regulated motion. Secondly, it has inertia, or mass—the property of conserving vis viva. Thirdly, it has some bond with its fellow by which the motions of both are modified by a constant stress according to a definite law of distance, and this, following Newton, we call attraction. Fourthly, it has the complex property of interchange of momenta, accompanied by that of conserving and compounding motion by angular rebound upon an indefinitely near approach, which we name resilience, or repulsion. Dimension it need not have, nor any other property of masses; but nobody has ever yet succeeded in getting rid of the above four. This is not universally recognized, however, and the recent controversies of philosophy are owing to the strenuous attempts to reduce the number, especially of those called occult. Motion being in our ordinary experience a result, has not been so classified, and indeed has only more recently been recognized as primary. It is with causes that philosophy seeks to deal, and in our experience causation is a chain. Primordial motion, however, is as occult and mysterious as static force.

One class of philosophers, recognizing the self-existent character of motion, has exhausted ingenuity in the effort to deduce attraction from it, of course wittingly or unwittingly bringing into co-operation the occult force inertia, to obtain vis viva. Another class would deduce all motion from attraction: while in the attempt to contrive a mechanism to explain resiliency—the most incomprehensible of all in a body without parts—immensely greater complications and difficulties have been introduced. Inertia, so far as I am aware, has always been accepted as an inscrutable fact, or ignored.

An entity with four unexplained properties is regarded as still a long way from satisfactory simplicity. But a more important consideration is that the entity is always found associated with its fellow or fellows in a dependent and artificial way (when identified at all), which indicates an advance from primitive independence and simplicity. The complexity of the simplest atom we know of has already been referred to. The resemblance of the atoms to manufactured articles was pointed out by Sir John Herschel; and not only that, but they resemble articles made in quantities by machinery, all exactly alike, like Waltham watches or Springfield guns. And the fact that any recognizable atom, like that of hydrogen, for instance, is always exactly the same thing, whether derived from the ocean or the coal measures, or from the occluded gas of a meteorite, or inspected in the sun and stars, as pointed out by Maxwell ("Encyclopædia Britannica," ninth edition, article "Atom"), would seem to indicate that it must be the result of an undeviating process, and in its ultimate derivation made up of finally discrete entities, and not out of continuous substance, whatever that may mean. The fact, too, of its occurrence at such wide points of distribution, indicates the unity of the present scheme of evolution, as well as the great antiquity of its origin, and its persistency of type.

We have at present no clew to the evolutionary history of the atom. The atom I distinguish both from the ultimate particle without parts, and from the complex derivative molecule of the chemical elements, such as all those we know of are. In fact, these must also be distinguished from the still differently organized compound molecule of the chemical combinations, which can be taken apart, and the enormously complicated system of the organic molecule, as of oil or albumen, which, if a body so simple as iron contains more than seven hundred couples, must contain rotary elements which can only be numbered by millions.

The atom, or elementary couple, is conceived as having dimension, figure, and polarity, and also perfect elasticity, by reason of its harmonic vibration. We have to seek an origin for it if we are at all impressed with its artificial and evolved character. Its artificiality lies in its rotary motion; such motion being due to and maintainable only by a composition of forces.

The weight and ponderosity of matter have proved a stumbling block to the conceptions of the later philosophers—especially after Newton had generalized them as attraction and inertia—far more than the equally unexplainable property of resistance, though why, it is difficult to say. Lucretius found no such difficulty with the conception of weight, for his corpuscles all naturally tended "downward," so uncosmical were his ideas. Le Sage revived and modified the hypothesis of Lucretius, especially to get rid of the (to him) inconceivable notion of gravity. Those kinematists who follow Le Sage do so with the same avowed motive. Another school, with the same view, have revived the continuous notion of matter; out of which they have constructed an atom which has permanence and elasticity, but no avowed occult affection except inertia. It has not been further developed.

The difficulty in accepting the fact of gravity seems to be a metaphysical one, though even the metaphysicians have not held that conceivability is a criterion of objective truth. The irrelevancy of this objection has been well stated by Mr. W. R. Browne, in his article on "Central Forces" ("London, Edinburgh, and Dublin Philosophical Magazine," January, 1883, page 40), as follows: "I am not aware that the term 'unthinkable,' which is a new one, has ever been defined. Until it has been, it is impossible to say whether action at a distance is unthinkable, or whether the fact of a conception being unthinkable is sufficient reason, or any reason, for holding it to be untrue." The many instances of unthinkable truths within our familiar knowledge will readily recur to all in illustration, as, for instance, the infinite extension of space, the infinite approach of asymptotes, the nature of interminable series, etc. In fact, all forms of absolute knowledge are unthinkable. The refusal to recognize this form of knowledge has led to much heresy in other branches of exact inquiry—even in mathematics. The sentiment, however, such as it is, has led to many ingenious and futile devices in the branch we are now considering—among others, the invention of the vortex atom, before referred to.

The vortex atom belongs, not to physics, but to purely mathematical concepts; being an ideal abstraction—as much so as a surface, or a line, or four-dimensioned space—invented for the purpose of investigating problems in hydrodynamics. A homogeneous, incompressible, continuous, perfectly mobile but not miscible substance is an impossible entity, and it would seem an inconsistent one as to mobility; and, if vortex motion can not be destroyed in it, it is equally true that no means can be devised for originating it. An occult force had to be attributed to it, after all, as mass. Helmholtz, its inventor, discussed it as a purely mathematical problem; but its British adopters, struck with the remarkable attributes deduced from the postulates, set it up as the basis of a kosmos. By a similar appreciation, when that characteristic product of British genius, a modern plow, was carried to India—the land of theosophic contemplation—its enthusiastic foreign admirers, after having been carefully shown its merits, and instructed in its use, were found to have erected it in the center of the field as a god!

But, though we have no need of the hypothesis of an ether to explain away the weight of matter, especially since no such invention has been so perfected as to prove particularly successful for the purpose, the establishment of the ether with any demonstrated properties might aid our conceptions of matter, and be concatenated with it as one of its higher forms. Maxwell has pointed out ("Encyclopædia Britannica," ninth edition, article "Ether") that, though many ethers have been proposed for various purposes, none have survived except that which was invented by Huygens to explain the propagation of light. Evidence accumulates for this hypothesis, in some form, for we have no other way of accounting for the facts, but the mechanism is still a mystery.

The very property of the supposititious ethers which is so fatal to all explanation of a static stress, like gravity, namely, the requirement of time for their functions, qualifies them so far as a vehicle of radiant manifestations. Were it not for the transmission of radiant energy in specific time, doubtless it would be far simpler and more satisfactory to explain the whole effect as actio in distans, under the necessary law of conservation, or on the Cartesian principle of contact. The phenomenon of electro-magnetic induction—which is believed to occur between the earth and sun, as a real material effect manifest in converted energy, and yet acting in lines transverse to the lines of transmission, and apparently simultaneous—even now outstands as unexplainable in any other way, for its mechanism certainly can not at present be comprehended. Nor is the mechanism for the transmission of the radiant forms of energy yet clearly made out, though some postulates about it having consistency and probability have been laid down. The fact that something supra-material is necessary and probable on other grounds gives encouragement to the idea that a basis for the atom can eventually be found.

The ether has been conceived under four principal modes of structure, all fashioned out of our concepts of matter. Two of these are static, and two kinetic. The first is the pseudo-concept of a continuous, colloidal plenum. This is a metaphysical, not a physical, concept; derived from an idealization of a false observation of matter which can not be realized consistently in thought with what is postulated of it afterward. As Maxwell happily remarks about the notion of homogeneous and continuous matter ("Encyclopædia Britannica," ninth edition, article "Atom"), "it is in its extreme form a theory incapable of development."

The second concept is that of a solid. This has been assumed as a conceivable way of accounting for the very high co-efficient of elasticity required by the undulatory theory, and also for the transverse mode of transmitting vibrations exhibited. The word "solid," however, can not have any meaning such as we ordinarily attach to it; and under any signification it is admitted that the theory is encumbered with several difficulties, some of which have been set forth by Professor G. G. Stokes, in his "Report on Double Refraction" ("British Association Report," 1862, p. 253).

Thirdly, the ether has been conceived to be the ordinary elastic gases or atmospheres freely expanded into space. But these have no co-efficient of elasticity sufficient to give them such expansion, and they would be liable to condensation and compression by their own gravity about the planets, which would cause a rise of temperature and dissipation of energy which would rob the ether of its permanent character. Besides, Maxwell has shown that our atmosphere expanded into space would be far too rare in the interplanetary spaces to satisfy the required conditions; nor is there any molecular velocity at all adequate to the propagation of wave-energy with the velocities observed, as will be shown further on.

This brings us to the fourth concept, which is that of a pure primordial gaseous plenum, of sufficiently high tension, and in the condition assumed by gases in a rarefied receiver, where the mean path is so long in proportion to the mean distance that a symmetrical movement arranges itself, according to the law first pointed out by Maxwell as a corollary from the equilibrium of pressure observed in confined gases, and the performance of gases in a rarefied space first observed by Crookes, that particles in free collision in space tend constantly to rearrange their motions automatically so as to move uniformly in all directions in radial lines from every point. With the gases experimented with the mean path at normal pressure and density is very short (only about 1260000 of an inch when the molecules have a mean distance from each other of 17000000 of an inch), but, at the extreme of rarefaction which we are able to effect (about 11000000 of an atmosphere, when the distance of the molecules is still only 170000 of an inch), the mean path rises to about four inches; and C. T. Preston has shown ("Nature," vol. xxiii, p. 463), that could we carry the exhaustion to the third power of that obtainable, so that the distance of the molecules apart should be so much as one seventh of an inch, the mean path would be raised to 60,000,000 miles, since it increases in the triplicate ratio with the distance. But with the ether no such rarity need be postulated, since mean free path is but a question of size of molecule, and in comparison with the hydrogen-molecule the size of the particle can only be infinitesimal. It is clear, however, that, with the enormous velocity due to the particle, all the effect of continuity would be produced, so far as vision is concerned, by a mean distance apart, not merely of one seventh of an inch, but of many miles.

We may therefore assign to the ether any required free path, and any necessary density, tension, and velocity, all of these latter being imperceptible to molecular structures which float in and are permeated by it. The motions also of molecules in a gas so constituted would be practically as unaffected as in free space, since it is demonstrable that the resistance to motion offered by a medium such as the hypothesis calls for would be in the ratio of the motion of the moving mass to that of the particle of the medium, which in the case supposed would be excessively small, the velocity of the radiant particles being equal at least to that of the transmission of light.[3]

It is clear that, by the use of the term "free path" by the inventors of this form of the ether, its particle had already been tacitly endowed with the ocult properties of inertia and resilience. Primordial motion was also attributed—an occult factor, which, with the other two, constitutes and conserves energy.

Such an ether serves to explain the phenomena of light, and the other radiant modes of energy, better than any other yet proposed. It, therefore, measurably serves its purpose. Prior to its invention, we had only—first, Newton's hypothesis of corpuscular emission, instantaneously propagated with explosive violence at an enormous but still uniform velocity, in all possible directions, in radial lines, which still were able to fill space at all points to unlimited distances—infinite and impossible results from a trivial cause; secondly, we had Huygens's scarcely more credible hypothesis of undulations, propagated, with the same instantaneous and uniform velocity in all directions, from a luminous point in a pervading statical solid or fluid medium—another infinite effect from a trivial cause. But by the hypothesis of its own independent linear motion, ever conserved—the parasitic energy alone being transferable, and by a mechanism different from the translatory motion—many difficulties are got over. The conservation of the linear motion is due to the law of radiant matter above stated, and also, I conceive, to another consideration, which tends to prevent the bombardment of the molecules, and consequent rise of temperature and distribution of energy, so fatal to the gravitation theory. It is that the only obstructive portion of the so-called material atom (which I have named the elementary molecule) lies in the extreme boundary; and even of this it constitutes only such fraction as the ratio which the dimension of the component particle bears to the semi-circumference of the atom, which is an infinitesimal ratio. The component, having a dimension and velocity of an order comparable with that of the ethereal particles themselves, can protect itself from collisions by a readjustment, without rise of temperature, on the same terms as obtain with ethereal collisions. Collisions, however, would be excessively rare—as much so as those of the particles among themselves—and an occasional collision could not destroy the atom, owing to the peculiar bond of the component with its fellow; but its motion would be merely compounded into a gyration. The real field of attraction and bombardment would be the void focus of the disk, toward which the resultant of all the forces in the ring would tend, as a corollary from the deduction from synchronism that the force which binds the atomic couples varies directly as the distance, instead of as the inverse squares.

In its passage through the disk-atom the ray takes up and conserves the dropped motion as a transverse vibratory motion of some kind; or, as Maxwell styles it, "some vector property which does not interfere with the motion of translation" ("Encyclopædia Britannica," ninth edition, article "Ether"), and which it can impart again to the revolving systems of atoms through which it travels, in an inverse mode to that of its derivation. The invention of the mechanism of this vector motion has its difficulties. I consider, first, that the radiant energies are not exhibited in matter, except upon a certain degree of disturbance, showing itself in a violent clashing of systems, either from the forming of new combinations or from incandescence resulting from the accession of energy from without or within. These clashings disturb the equilibrium of the atomic orbits, and occasion their rapid deformation by harmonic vibration in elliptic orbits whose rectangular axes rapidly alternate from major to minor while the agitation is kept up. Now, the circular movements of the components do not disturb the uniform transit of the linear ray; but the rapid approach and recession of the components in passing through the violent elliptical transitions cause a rapid alternation of stress in the field of stress through which the rays pass—since the stress varies as the distance of the components—causing a vibratory deflection of the stream of particles, due to the variation of the attractive force, in all rays except the polar ray, and in the plane of the ray normal to the plane of stress. Since the disk-atoms lie in all planes, we shall have transverse vibrations in all directions; but, if the rotating disk is gyratory, as would be the rule and not the exception, the identical ray would receive a vector or corkscrew motion, similar to what is called for by observation. The amount of deflection I take to be the index of refraction of the molecule.

It may seem unaccountable that the whole ray should undulate from passing through a single locality of oscillatory disturbance, being composed of discrete and unconnected particles; but we may compare the parallel phenomenon of a jet of water, forcibly ejected to a great distance through a hose-nozzle, which exhibits to the eye similar undulations when the source of discharge is slightly and rapidly oscillated.

It may also seem incredible that any orbital movements could be permanent enough to sustain oscillatory vibrations of such inconceivable frequency as those which luminous rays are known to execute; but I have computed, from the probable dimensions of the hydrogen molecule as assigned by the molecular physicists, and an orbital velocity due to an ethereal origin for the components, that many hundreds of revolutions must occur for each transverse oscillation or elliptical deformation.

In its passage through other disk-atoms in equilibrium which are in harmonic tension with the vibrating ray (and therefore not diathermia or transparent), I conceive that the vibratory ray is able to invert the process and agitate the diaphragm of stress of the system, as a fish-line does the surface of a pool; thus setting up an inverse commotion and vibration of orbits due to accession of motion, accounting: for the effects of reflexion, the absorption and conversion of light into sensible heat, and the chemical and actinic and electrolytic effects observed. The diverse nature of some of these effects may be due to the extremely diverse character of the vibrations, both of the disks and of the rays; e. g., the polar ray, which would have a pulsatory vibration.

The primitive gas would not, any more than our own elementary gases, experience any difficulty in holding its own, and maintaining equilibrium forever, under any ordinary state of diffusion, by reason of its perfect elasticity. But with emerging matter, or crippled ether, among other properties gravity becomes apparent; and though hardly sensible, at first, yet within the enormous cosmical aggregations of this novel drift, pressure and condensation would ensue at some point so great that in the absolute cool of space the critical point of endurance would be overcome, and some molecular systems would cripple and collapse, with the resultant liberation of their motion and clashing and agitation of the neighboring systems known as rise of temperature. The falling in of others would follow and increase the commotion, causing local expansion, and currents to a region of less pressure sometimes, no doubt, with enough velocity to carry them entirely into free space, and beyond the control of the system.

It would be futile to attempt here to follow out all the complex consequences of this initiated evolution, but it is clear that the temperature of the whole aggregation must rise until, at the outer boundary, where alone the liberated energy was able finally to escape, the temperature must stand constantly at the heat of dissociation of the particular element or elements being evolved at any stage of development. But radiation would proceed only at the rate allowable by the nature of the combinations going on at a specified stage, though it would be practically constant for long periods, as the supply of motion could be extricated. The aggregation could not become a simple cooling body while molecular mobility remained.

Amid all this commotion and lavish escape of energy on the wings of the ether, not one particle of matter is lost. It can not recover its linear motion. It joins in the dance that is going on, and contributes to swell the molecular weight of whatever system of molecules is being evolved at that particular stage of development.

The absolute synchronism exhibited under all amplitudes of vibration by the disk-atom indicates the same law of central force as that of the pendulum in its synchronous forms, or the spring-governor; and if attraction be the bond, it is a similar law of attraction, namely, directly as the distance. This is the Newtonian law of gravity within the homogeneous sphere, and thus by actual demonstration the attractive atom observes the same law as would the earth were it penetrable—namely, the inverse squares of the distances within the sphere.[4]

The identity of the radiant particle with the component of the atom is inferable. It possesses the requisite properties of mass and resilience, and sufficient linear motion. Whether it should also have attraction imputed to it as inherent depends on whether that property in the molecule, where alone it is observed, is derived from the particle. If not, the latter needs only mass to conserve its deflections and its course under the first law of motion, and resilience to secure its compensatory readjustment in equilibrium. Even if possessed of gravity, the enormous proper velocity of the particle would render such an affection totally undiscoverable, because the Newtonian curves of the second order resulting from the composition of force could be nothing less than hyperbolas, whose branches would be wholly undistinguishable from straight lines.

No means at present offer themselves for suggesting how such a discontinuity of action as is implied by the change from simple linear motion to the balanced movements of the atoms could have occurred; and especially how a law of attraction according to inverse squares of distance, which we must postulate, could change for one so extraordinary as that observed within the atom, namely, directly at the distance. The law referred to rather resembles that of our summer whirlwinds, wherein the centripetal force, i. e., the pressure from without due to the rarefaction within, seems to vary directly as the centrifugal force, and therefore as the radius, until equilibrium of rotation is established. These also display a species of attraction within the vortex; and some forms of matter—as iron—evince a similar polar attraction at sensible distances when rearranged by vortical motion. But such a theory does not commend itself by that simplicity which we should expect in the region of the atom.

The evolution of the atom or elementary molecule from the particle, even if real, is not continuous with the present order of nature within our observation, and need not be, any more than the formation of a storm-cloud is a continuous process in the atmosphere, or the appearance of a rash in the human patient is continuous. But the cataclysm once accomplished, a new uniformity must have supervened, and evolution proceeded from that point continuously from the simple to the more heterogeneous, in accordance with strict dynamical law. Even now the history of such evolution is as plainly to be read as the history of the growth of plants in a forest. Some of the nebulæ give evidence of being collections of the simplest primordial gases, or mixtures of such, by the simplicity of their spectral lines. Even in these, radiant energy is being set free, or we could not know of their existence. We also know that the sun and stars are tremendous laboratories for the organization of matter, where disused motions are liberated in torrents. The creation of molecules in gradually increasing complexity seems to go on by discontinuous steps or stages, in accordance with the discontinuous and discrete nature of the elemental factors; and its products at each certain stage are all duplicates, whether in this sun or that. Every increase in complexity apparently liberates motion, which, by the law of conservation, must escape as an efficient agent. With the constant escape of energy, however, solidification finally ensues, as our planet bears witness, and the mobility of the molecules practically ceases. Gases and moisture, however, remain over to supply mobile conditions, and the work goes on. At this stage new supplies of sufficient temperature from without are capable of reversing the process to a degree, restoring mobility, and introducing new modes for the play of affinities. The radiant energies of the sun supply for our planet the extraneous motion necessary to carry the complexity of the molecule higher than the simple running down of matter can do, and we have the chemistry of the carbon compounds. Aided by some discontinuous step, which we can not as yet identify or explain, vitalized functions appear. The wondrously compound molecules of the tropics are evolved, oils, starches, sugars, spices, ethers, and alkaloids—magazines of stored-up vis viva—and, by the assimilation of these, physiological phenomena in sentient beings are carried on, accompanied by the mysteries of will and consciousness, and the still more unaccountable facts of succession and heredity, which mock, if material, all efforts at conception or comprehension of matter in its ultimate essence.

The actual amount of energy stored up in the elementary molecule is not calculable, but it must be enormous. The amount of motion can not be certainly known, for we do not know whether any could have disappeared at the birth, and the mass or atomic weight of the ultimate particle can not be known by any means now in possession. The great rapidity of oscillation across the small orbit has been vividly illustrated by G. J. Stoney ("London, Edinburgh, and Dublin Philosophical Magazine," August, 1868, page 132), by the consideration (since numbers convey no idea) that they bear the same ratio of frequency to a second of time that a second (or a wave of the hand) bears to 30,000,000 years—one of the geologic periods, during which a race of animals may have been evolved and have perished.

Such inconceivable velocity of rhythmical motion in the elementary molecule points to some cause more potent than the action of any mere static force combined with any mere energy of position. The same is true of the more complex molecules of our experience—say of iron, or calcium—displaying hundreds of spectral lines. We can not suppose these inconceivably energetic motions to have been all set up by any mere precipitation which evolved the element, nor to have existed in their present organization from eternity. The same is, of course, true of the organic molecule. Their conserved energy lies in the vast reserve of vis viva stored up in their complex interior movements. A few ounces of organized food suffice for the expenditure of a mountain-climber for a whole day. An apparently inert explosive is traversed by a tiny spark, or pressed too closely, and the increased swing of one molecular orbit sets off the whole mass into new paths and more economical relations by which a vast amount of motion is liberated, to appear as temperature. This temporarily expands the w r hole mass many volumes, but, as the agitation subsides, the now surplus energy dissipates by radiation, and, being picked up by surrounding bodies, temperature becomes equalized. This mechanical modification and distribution of motions, resulting in final equilibrium, is more intelligible than the instantaneous setting up of immense velocities and momenta by precipitation from a state of absolute rest.

Besides, research proves that there is absolutely no room for any such energy of position as was fancied. Sir William Thomson has shown, by considerations of high probability ("Nature," vol. i, page 553), that the distance from center to center of molecules in solids and liquids can be but little more than the diameter of the molecules. In liquids, from their great resistance to compression, the practical point of contact has been reached, but temperature conserves mobility.

The phrase "dead matter," once deemed so eminently characteristic, now seems absurd. To deprive matter of its inherent activity is indeed one of the most difficult problems we can encounter. To do it, some means for the disposal and transfer of its energy must be provided. Until very recently, no means were contrivable for subduing the elementary gases, but, by resorting to the most extraordinary compression, in conjunction with the lowest temperature procurable by artificial means, the feat has been accomplished. There is a way, however, of pitting certain elements against each other by taking advantage of their commensurate atomic periods, and in this way we get our chief supply of artificial heat. This is due to our fortunate store of carbon and hydrogen, free and combined, and of uncombined oxygen. The known distances of the molecules of the gases above named under normal temperature and pressure give no clew to the enormous amount of energy liberated by their combination under any supposable attraction—certainly not under any that is observable.

We are, therefore, compelled to recognize the latent energy in matter. The kinematists were profoundly impressed by this now established fact, and, as is the usual tendency of the promulgation of any brilliant discovery, they undertook too much with it—to wit, to construct a kosmos.

By a similar tendency, after the establishment of the laws of motion, and of universal gravitation, followed by the discovery of the conservation of matter, and later by that of the conservation of energy, and the perception of the energy of position, these brilliant advances in knowledge of the absolute had encouraged the hope that the ultimate could be explained. Matter was then viewed almost entirely in its statical aspect—as is even now too much the case, for we still see in our chemical text-books molecules absurdly represented by geometrical diagrams—and, from the fact that motion does actually result from attraction and position, it was natural to relegate motion to the category of effects. There were, then, but two factors in the problem—matter, and its occult affections. But as matter they took the old "dead matter," in the last gasp of its evolution, freighted down with its bundle of inert properties of negation, and, to evolve a universe, simply credited it with its virtue of position, and left it to the action of the weakest of its affections, gravitation, to run over again a short portion of its normal course.

Even then, the surprising result appeared that it would galvanize itself into life with activity enough to supply the radiant energy which our sun now exhibits for a period of some 20,000,000 years. This, whether we follow the meteoric hypothesis of Mayer, or the contraction hypothesis of Helmholtz, which have been held to be the only conceivable hypotheses. How sublime the solution of the problem could we, in the place of these cinders, put into the mathematical mill the true data! James Croll, in groping for some adequate data to explain the duration actually needed for the exhibition of solar energy of which we have evidence, suggests ("Climate and Time," page 353) that, on dynamical principles, given two masses each one half the sun's mass, moving directly toward each other with a velocity of 476 miles per second, sufficient heat might be accounted for to cover an emission at the present rate for 50,000,000 years. The surplus velocity, over and above that due to gravity, he derives from stellar proper motion; but, while the supposition is violent and unphilosophical, both in respect to the large proper motion assumed, and particularly as to the assumption of direct collision, in the plurality of cases called for by the multitude of suns, the result is still grossly inadequate. The problem is insoluble from pure dynamical considerations. They take no heed of the most important factors—elementary specific heat, elementary affinities, elementary motion. When we once succeed in legitimizing the conception that suns and stars are evolved, not out of débris, and weak statical force, but from the primordial plenum itself, equipped with latent power in equilibrium, we can view them as they apparently are—perennial fountains of energy—incandescent lamps of eternity—drawing their supplies from the mysterious stoppage of primordial motions, with the accompanying evolution of chemical elements, and the radiation of liberated energy in torrents.

Energy of position is undoubtedly a factor, among others more important, in an evolving nebula or sun. It should be given its due value, but no more. There is evidence to show that even the translatory motions of suns and worlds can not be wholly accounted for by gravity alone. This is furnished by the large proper motion of some of the stars, particularly the notable instance of 1830 of Groombridge's catalogue, with a linear velocity of at least two hundred miles per second, if observations are to be trusted. An analysis by Newcomb proves conclusively that all the stars of the visible portion of the universe, and all the possible dark masses which could exist there, are widely incapable either of furnishing a star with such an amount of motion, or of stopping it.

The recognition of kinetics, then, in conjunction with dynamics, is what I desire to call attention to, in our philosophical attempts to extend our generalizations. We need to take note of all the forces and factors which we can perceive; and even then it is probable that our field of inspection will be too restricted to yield a satisfactory insight into that which was born from eternity. But that should not induce us to settle down on a "good enough universe" for finite comprehension, nor plead for boundaries to the infinite and eternal. Some mathematicians have invented a space cut down to finite comprehension. The trouble with these finite infinities and limited universes is, that they do not satisfy the mind, nor the definitions.

Although the course of the present order of creation is far longer than can be assigned or imagined, and, even as to our solar system, illimitable as measured by our cycles, no doubt it runs its course, for we can see the evidence of progressive change. The struggle for the elimination of energy in its entanglement with mass is a fiercer and more protracted one than we dreamed of, but it goes surely on to its termination. The energy by which the small vehicles were possessed escapes by slow dissipation back into the great storehouse of equilibrated power whence it was arrested, as gases return to the parent atmosphere from the rotting wood of the forest. The molecule is never finally taken apart, that we can see. The skeleton-heaps, in rigid and icy bonds, wander forever as débris and dust through the streams of space. Their amount, however, is so infinitesimal compared with the infinite magazine of their elements which has never been subject to change throughout the eternities, that they may be regarded as but the calculi resulting from the merest nodules of local and temporary inflammation—imperceptible to the health of the infinite corpus.

Thus I admit, with the pure dynamist, that the material universe, or successive material universes (if such a solecism is pardonable), as manifestations of matter and motion, are concatenated with time, are born, run their course, and fade away, as do the clouds of air. But the infinite reservoir of power wherein they occur as disturbances remains. What can cause these manifestations of power—these droopings of energy, with their complicated results? This is beyond our finite ken; but it is certain that the mere running through of its course of a finite evolution does not end the eternal, the infinite, and absolute. Nor can the mind be restricted to such a conception by any argument about the limitation of its faculties.

1. Read before the Philosophical Society of Washington, January 27, 1883.
2. Annual Address before the Philosophical Society of Washington, 1882, p. 24.
3. The velocity would really be at least one third greater. It has been shown, by a calculation of Maxwell's ("London, Edinburgh, and Dublin Philosophical Magazine," 1877, p. 453), that, in a gas constituted as assumed, the velocity of the wave-motion would be to the velocity of the particle in the ratio of the ${\displaystyle \scriptstyle {\sqrt {5}}to3;}$ that is, about ·745+; which would give a velocity for the ethereal particle of nearly 250,000 miles per second. It is highly probable, moreover, that some forms of electrical radiant energy surpass light in velocity of transmission.
4. This parallel holds good only for the balanced couples themselves, in which I have assumed the cause of the stress to reside. The intensity of the stress would not vary as the distance from the center for a third body, as in the permeable sphere, but the field would be like a strained elastic tympanum, with varying tension dependent on the separation of the elements. The mathematical discussion of this field of force would be most interesting, involving, as it does, the investigation of all the phenomena of refraction and reflexion.