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Popular Science Monthly/Volume 3/September 1873/The Constitution of Matter

< Popular Science Monthly‎ | Volume 3‎ | September 1873

THE CONSTITUTION OF MATTER.
By FERNAND PAPILLON.

TRANSLATED BY A. R. MACDONOUGH.

WHATEVER empirics and utilitarians may say of them, there are certainties apart from the experimental method, and there is progress disconnected with brilliant or beneficent applications. The mind of man may put forth its power in laboring in harmony with reason, yet discover genuine truths in a sphere as far above that of laboratories and manufactures as their sphere is above the region of the coarsest arts. In a word, there is a temple of light that unfolds its portals to the soul neither through calculation nor through experiment, which the soul nevertheless enters with authority and confidence, so long as it holds the consciousness of its sovereign prerogatives. When will professed scientists, better informed of the close connection between metaphysics and science, whence our modern knowledge of Nature has sprung, better taught in the necessary laws that govern the conflict of reason with the vast unknown, confess that there are realities beyond those they attain? When will science, instead of the arrogant indifference it assumes in presence of philosophy, admit the fertility beyond estimate of the latter? It may be that the hour of this reconciliation, so much to be longed for, is less remote than many suppose; at least, every day brings us nearer to it. The spirit of Descartes cannot fail to arouse before long some genius mighty enough to revive among us a taste and respect for thought in all the departments of scientific activity. Deserted as high abstractions are for the moment, they are not, thank Heaven, so utterly abandoned as to deprive study of its ardor, and essays of their success, when these relate to the problem of the constitution of matter. In fact, this is a question which for several years past has occupied some among our own savants and thinkers, as completely as it has employed most of those of the rest of Europe, a question which bears witness with peculiar eloquence to this fact, that, if philosophers are forced to borrow largely from science, in its turn science can retain clearness, and elevation, and strength, only by drawing its inspiration from, and recognizing its inseparable connection with, the abstract consideration of hidden causes and of first principles.

 
I.

Matter is presented under a great variety of appearances. Let us consider it in its most complicated state, in the human body, for instance. In this, ordinary dissection distinguishes organs, which may be resolved into tissues. The disintegration of the latter yields anatomical elements from which direct analysis extracts a certain number of chemical principles. Here the anatomist's work ends. The chemist steps in, and recognizes in these principles definite kinds arising from the combination, in fixed and determinate proportions, of a certain number of principles that cannot be decomposed, substantially indestructible, to which he gives the name of simple bodies. Carbon, nitrogen, oxygen, hydrogen, sulphur, phosphorus, calcium, iron, which thus set a limit to experimental analysis of the most complex bodies, are simple substances, that is to say, they are the original and irresolvable radicals of the tissue of things.

We now know that matter is not indefinitely divisible, and that the smallest parts of the various simple substances existing in those that are naturally compound have not all the same dimensions, nor equal weights. Chemistry, by a course of analyses and measurements, has succeeded in determining the weights of atoms of the different elements, that is to say, taking as a unit an atom of the lightest element, hydrogen, in determining the weight of the atoms which are equivalent to this conventional unit in the various combinations. Though many savants continue to maintain that atomic weights are nothing but relations, and that the existence of atoms is a mere logical device, it seems more reasonable to admit, with the majority of those who have studied this difficult problem closely, that these atoms are actual realities, while it may be very far from easy to settle precisely their absolute dimensions. In any case, we may affirm that these dimensions are very much less than those presented by the particles of matter subjected to the most powerful and subtle methods of division, or decomposed by the imagination into its minutest elements. "Let man," says Pascal, "investigate the smallest things of all he knows; let this dot of an insect, for instance, exhibit to him in its diminutive body parts incomparably more diminutive, jointed limbs, veins in those limbs, blood in those veins, in that blood humors, and drops within those humors—let him, still subdividing these finest points, exhaust his power of conception, and let the minutest object his fancy can shape be that one of which we are now speaking—he may, perhaps, suppose that to be the extreme of minuteness in Nature. I will make him discover yet a new abyss within it. I will draw for him not merely the visible universe, but all besides that his imagination can grasp, the immensity of Nature, within the confines of that imperceptible atom." In this Pascal displays a feeling as true as it is deep of the infinitely small, and it is interesting to observe how the amazing revelations of the microscopic world have justified his eloquence and foresight; and yet this microscopic world, whose minutest representatives, such as vibrios and bacteria, are hardly less than the ten-thousandth part of 125 of an inch, how coarse it is compared with the particles thrown off by odorous bodies, and with the inconceivably minute quantities which chemistry, physics, and mechanics, now measure without seeing them, or make their existence plain without grasping them! We may mention some instances which can give us an idea of these.

According to Tyndall, when very minute solid particles, smaller than the luminous waves, are diffused in a medium traversed by light, the light is decomposed in such a way that the least waves, the blue ones, predominate in the reflected rays, and the largest ones, the red waves, in the transmitted rays. This ingenious physicist thus explains how the blue color of the sky depends and must depend on the existence of solid particles, excessively minute, diffused in infinite quantity through the atmosphere. Tyndall is not disinclined to the idea that these imperceptible atoms might very well be no other than those germs of microscopic organisms the presence of which in the atmosphere has been proved by the labors of Pasteur, as well as the part they take in the phenomena of putrefaction and fermentation. The ova of these beings, which are barely visible under the microscope after attaining full development, and of which the number, ascertained by the most decisive evidence, confounds the boldest imagination, these would be the elements of that vital ether, as we have termed it, that dust which gives its lovely blue tint to the vault of the sky. "There exist in the atmosphere," Tyndall says in closing, "particles of matter that elude the microscope and the scales, which do not disturb its clearness, and yet are present in it in so immense a multitude that the Hebrew hyperbole of the number of grains of sand on the sea-shore becomes comparatively unmeaning." And to give an idea of the minuteness of these particles, Tyndall adds that they might be condensed till they would all go into a lady's travelling-bag. Manifestly these particles escape any kind of direct measurement and observation. Their objective reality can no more be demonstrated than that of the particles of ether can be made evident. Yet there are certain facts which aid us to form a clear conception of them. Let us dissolve a gramme of resin in a hundred times its weight of alcohol, then pour the clear solution into a large flask full of pure water, and shake it briskly. The resin is precipitated in the form of an impalpable and invisible powder, which does not perceptibly cloud the fluid. If, now, we place a black surface behind the flask, and let the light strike it either from above or in front, the liquid appears sky-blue. Yet, if this mixture of water and alcohol filled with resinous dust is examined with the strongest microscope, nothing is seen. The size of the grains of this dust is much less than the ten-thousandth part of 125 of an inch. Moren makes another experiment, proving in a still more surprising way the extreme divisibility of matter: Sulphur and oxygen form a close combination, called by chemists sulphuric-acid gas. It is that colorless and suffocating vapor thrown off when a sulphur-match is burned. Moren confines a certain quantity of this gas in a receiver, places the whole in a dark medium, and sends a bright ray of light through it. At first nothing is visible. But very soon in the path of the luminous ray we perceive a delicate blue color. It is because the gas is decomposed by the luminous waves, and the invisible particles of sulphur set free decompose the light in turn. The blue of the vapor deepens, then it turns whitish, and at last a white cloud is produced. The particles composing this cloud are still each by itself invisible, even under strong microscopes, and yet they are infinitely more coarse than the primitive atoms that occasioned the sky-blue tint at first seen in the receiver. In this experiment we pass in steady progress from the free atom of sulphur parted from the oxygen-atom by the ether-waves to a mass apparent to the senses; but, if this mass is made up of free molecules which defy the strongest magnifiers, what must be the particles which have produced those very molecules!

A last instance of another kind will complete the proof as to the minuteness of the elements of matter. When a clear solution of sulphate of aluminum is poured into an equally clear solution of sulphate of potassa, the mixture at once grows turbid, and after a few seconds myriads of little crystals, sparkling like diamonds, make their appearance in the liquid, which are nothing else than crystals of alum. If we suppose the diameter of these crystals to be 1/25 of an inch, it will follow from this experiment that in the lapse of a few seconds crystals had the power of producing themselves containing tens of millions of molecules, each composed of 94 atoms, grouped in admirable harmony. The motions of these chemical atoms take place under the influence of the same forces that guide the motions of those enormous agglomerations of atoms called stars. The revolution of one sun around another takes a thousand years, while these atoms in course of combination perform hundreds of millions of such revolutions in the millionth part of a second!

By varied and delicate calculations, Thomson has succeeded in establishing the fact that, in liquids and transparent or translucent solids, the mean distance between the centres of two contiguous atoms is comprised between the ten-millionth and the two-hundred-millionth part of 1/25 of an inch. It is not easy to form an exact conception of dimensions so small, of which nothing, among the objects that affect our senses, can convey any idea. Thomson judges that the following comparison may aid us to appreciate them: If we imagine a sphere as large as a pea magnified, so as almost to equal the earth's volume, and the atoms of that sphere enlarged in the same proportion, they will then have a diameter greater than that of a shot, and less than that of an orange. In other words, an atom is to a globe the size of a pea what an apple is to the terrestrial globe. By arguments of quite another kind, drawn in part from the study of chemical molecules, in part from the phenomena of capillarity, Gaudin has ascertained, for the dimension of the smallest particles of matter, figures very nearly the same as Thomson's. The maximum distance apart of the chemical atoms in molecules is the ten-millionth part of 1/25 of an inch. Gaudin follows Thomson in the attempt to give some sensible notion of the truly amazing minuteness of a dimension like this. He calculates, upon this estimate, the number of chemical atoms contained in about the size of a pin's-head, and he finds that the number requires for its expression the figure 8 folio wed by twenty-one ciphers. So that, if we attempted to count the number of metallic atoms contained in a large pin's-head, separating each second ten millions of them, we should need to continue the operation for more than 250,000 years!

There are, then, atoms in matter, and atomism is a fact, whenever we rest in the affirmation of the existence of atoms. But these are not the real principles, the simple and irreducible elements of the world. After decomposing sensible matter into atoms, we must subject the latter to an analysis of the same kind. Let us, then, consider any two heterogeneous atoms whatever, an atom of iron and an atom of hydrogen, for instance, and examine in what respect they can really, essentially, differ from each other. What is it which at bottom truly distinguishes these two atoms, as atoms? It is not any peculiarity of form, solidity, fluidity, hardness, sonorousness, brightness, because these properties evidently depend on the mutual arrangement and disposition of atoms, that is, because they are not relative to the individuality of each atom, but to that of the whole which they form by being grouped together. Neither is it any caloric property, or optic, or electric, or magnetic one, because these properties result from the movements of the ether, within the more or less complex aggregate of the respective atoms of these two substances. Now, if these atoms, taken separately, differ from each other in virtue of none of the properties just enumerated, they can only be dissimilar as regards two attributes, dimension and weight; but difference in weight results from difference in dimension, and is not a qualitative difference, but simply a quantitative one. Consequently, any two heterogeneous atoms whatever, compared together, as atoms, have scarcely any of the differential attributes peculiar to the groups which they make up by aggregation, and represent no more than two distinct functions, two different values of one and the same initial matter, of one and the same primitive quality or energy. This simple demonstration establishes the unity of substance, not as a more or less plausible physical hypothesis, but as a metaphysical certainty, alike underivable and necessary. If we add now, reserving the demonstration for a later period, that dimension, corporeal extension itself, as Leibnitz said and as Magy has lately proved, is only a resultant of force, it will become evident that matter, in the last analysis, is reduced to force.

Tyndall, in his biography of Faraday, tells us that one of the favorite experiments of this physicist gives a true image of what he was: "He loved to show how water, in crystallizing, eliminates all foreign substances, however intimately mingled they may be with it. Separated from all these impurities, the crystal becomes clear and limpid." This experiment is especially the true image of what Faraday was as a metaphysician. For him nothing had so great a charm as those serene transparent regions, in which science, cleared of impurities, appeared to his great mind in all the glory of its power and splendor. He yielded himself to it with absolute abandonment. He particularly loved to dwell upon the problem which is now engaging us: "What do we know of an atom apart from force?" he exclaims. "You conceive a nucleus which may be called a, and you surround it with forces which may be called m; to my mind your a or nucleus vanishes, and substance consists in the energy of m. In fact, what notion can we form of a nucleus independent of its energy?" As he holds, matter fills all space, and gravitation is nothing else than one of the essentially constitutive forces of matter, perhaps even the only one. An eminent chemist, Henry Saint-Claire Deville, lately declared that, when bodies deemed to be simple combine with one another, they vanish, they are individually annihilated. For instance, he maintains that in sulphate of copper there is neither sulphur, nor oxygen, nor copper. Sulphur, oxygen, and copper, are composed, each of them, by a distinct system of definite vibrations of one energy, one single substance. The compound, sulphate of copper, answers to a different system, in which the motions are confounded that would produce the respective individualities of its elements, sulphur, oxygen, and copper. Moreover, Berthelot long ago expressed himself in exactly the same manner. As long ago as 1864 that savant said that the atoms of simple bodies might be composed of one and the same matter, distinguished only by the nature of the motions set up in it. This decisive saying a great number of savants and philosophers in France and abroad have repeated and are still repeating, with good reason, as the expression of a solid truth.

If the smallest parts which we can imagine and distinguish in bodies differ from each other only by the nature of the motions to which they are subjected, if motion alone rules and determines the variety of different attributes which characterizes these atoms, if in a word the unity of matter exists—and it must exist—what is this fundamental and primary matter whence all the rest proceed? How shall we represent it to our minds? Every thing leads to the belief that it is not essentially distinguished from the ether, and consists in atoms of ether more or less strongly held together. It is objected that the ether is imponderable; but that is an unfounded objection. Doubtless it cannot be weighed; to do that we must compare a space filled with ether to a space empty of ether; and we are evidently unable to isolate this subtle agent, whose particles counterpoise each other with perfect equilibrium throughout the universe. Yet many facts attest its prodigious elasticity. A flash of lightning is nothing more than a disturbance of equilibrium in the ether, yet no one will deny that lightning performs an immense work. However this may be, it is impossible to think of the energies that make up the atom otherwise than as of pure force, and the ether itself, whose existence is demonstrated by the whole of physics, can be no otherwise defined than by the attributes of force. It follows from this that atoms, the last conclusion of chemistry, and ether, the last conclusion of physics, are substantially alike, although they form two distinct degrees, two unequal values, of the same original activity. All those physico-chemical energies, as well as the analogous energies of life, only show themselves to us, save in rare exceptions, clothed with that uniform we call matter. A single one of these energies shows forth, stripped of this dress, and bare. It rules all the others, because it knows them all without their knowing it. It is not power merely, but consciousness besides. It is the soul. How define it otherwise than as force in its purest essence, since we look upon it, as on the marble of the antique, in splendid nakedness, which is radiant beauty too?

Whether we consider coarser matter which can be weighed and felt, or that more subtle, lively, and active matter we call ether, or again the spiritual principle, which is energy simple, we have then always before us only harmonious collections of forces, symmetrical activities, ordered powers, more or less conscious of the part they play in the infinite concert for which the Creator has composed the glorious music. Let us set aside for a moment the variety of groupings which determine the succession and the manifold aspects of these forces, and there will remain, as constituent principles of the web of the universe, as irreducible and primordial ingredients of the world, nothing but dynamic points, nothing but monads.

The term of the rigorous analysis of phenomena is, definitively, the conception of an infinity of centres of similar and unextended forces, of energies without forms, simple and eternal. We ask what these forces are, and we assert in answer that it is impossible to distinguish them from motion. Force may be conceived, but not shaped to the fancy. The clearest and truest thing we can say of it is, that it is an energy analogous to that whose constant and undeniable presence we feel dwelling in our deepest selves. "The only force of which we have consciousness," says Henry Sainte-Claire Deville, "is will." Our soul, which gives us consciousness of force, is also the type of it, in this sense that, if we wish to pierce to the elementary mechanisms of the world, we are imperiously driven to compare its primal activities with the only activity of which we have direct knowledge and intuition, that is to say, with that admirable spring of will, so prompt and sure, which permits us every moment to create and also to guide motion.

Motion may serve to measure force, but not to explain it. It is as subordinate to the latter as speech is to thought. In truth, motion is nothing else than the series of successive positions of a body in different points of space. Force, on the other hand, is the tendency, the tension, which determines the body to pass continually from one to the other of these points; that is to say, the power by which this body, considered at any instant in its course, differs from the identical body at rest. Evidently this something which is in one of these two bodies and is not in the other, this something that mathematicians call the quantity of motion, which is transformed, on a sudden stop-page of motion, into a certain quantity of heat, this something is a reality, distinct from the trajectory itself; and yet nothing, absolutely nothing, outside of the inner revelation of our soul, gives us the means of understanding what this initial cause of the motive forces may be. The distinguished founder of the mechanical theory of heat, Robert Mayer, defines force to be "whatever may be converted into motion." There is no formula that so well expresses the fact of the independence and preëminence of force, nor so completely includes the assertion of the essential reality of a cause preëxisting motion. The idea of force is one of those elementary forms of thought from which we cannot escape, because it is the necessary conclusion, the fixed and undestroyable residue from the analysis of the world in the alembic of our minds. The soul does not find it out by discursive reasoning, nor prove it to itself by way of theorem or experiment; it knows it, it clings to it by natural and unconquerable affinity. We must say of force what Pascal said of certain fundamental notions of the same order: "Urging investigation further and further, we necessarily arrive at primitive words which cannot be defined, or at principles so clear that we can find no others which are clearer." When we have reached these principles, nothing remains but to study one's self with profoundest meditation, not striving to give an image to those things whose essence is that they cannot be imagined. From the most general and abstract point of view, then, matter is at once form and force, that is, there is no essential difference between these two modes of substance. Form is simply force circumscribed, condensed. Force is simply form indefinite, diffused. Such is the net result of the methodical inquiries of modern science, and one which forces itself on our minds, apart from any systematic premeditation. It is of consequence to add that the merit of having formulated it very clearly and noted its importance belongs to French contemporary philosophers, particularly to Charles Lévèque and Paul Janet.

 
II.

If the web of things, the essence of matter, is one single substance, who was the Orpheus under whose spell these materials gathered, ranged, and diversified themselves into natures of so many kinds? And, first of all, how can the extension of bodies proceed from an assembling of unextended principles? The answer to this first question does not seem difficult to us. Extension exists prior to matter. They are two distinct things, without any relation of causality or finality. Matter no more proceeds from extension than extension proceeds from matter. This simple remark suffices to settle the difficulty of conceiving how the dimension of objects results from a group of dynamic points which have no dimension. Extension existing before every thing else, it is quite clear that, when certain primal energies come into union to give rise, through a thousand successive complications, to phenomena and to bodies, what they really produce is not the appearance of extension, which is the mere shadow of reality, but it is that collection of various and diverse activities which enable us to describe and define phenomena and bodies.

It is no longer a subject of doubt, in the minds of savants who have got beyond experimentation, that extension is an image and a show rather than an essential constituent property of bodies. The extension of bodies is a phenomenon which takes its rise in the collision of force with our minds. Charles de Rémusat, so long ago as 1842, gave an original and remarkable demonstration of this. He maintains that force is the cause of extension, meaning by that that the sensation of extension is a modification of our sensibility, occasioned by forces analogous to those which produce sensations of a more complex kind. When you experience an electric shock, you are struck. Percussion is the sensation of contact, in other words, of impulsion by something that has extension. Now, in this instance, Rémusat says, the cause of percussion, electricity, has no extension. Therefore, he adds, either electricity is nothing, or else it is a force which affects us in a way that may be compared to the effect of extension. So that a force, wanting the usual appearances of extension, may produce the same effects on us that a solid body in motion does. Within a few years a profound metaphysician, Magy, has pointed out by new arguments that corporeal extension is merely a show which springs from the internal reaction of the soul against the impression made on the sensorium, and which the soul translates to outward bodies, by a law analogous to that which makes it localize in the separate organs of sense the impression which it has nevertheless perceived only in the brain. Each sensation of taste, smell, light, or sound, is a phenomenon of psychological reaction which occurs in the soul when it is teased with a certain degree of energy by nerve-action, which in its turn depends on an outward action; but there is no relation of resemblance between the latter and the sensation it provokes. The ether, which, by its vibrations in unison with the elements of our retina, produces sensations of light in us, has in itself no luminosity. The proof of this is that two rays of light meeting under certain conditions may annul each other, and produce darkness. Now, Magy maintains that the subjectivity of extension is of the same order with that of light. Extension in general is explained by purely dynamic reasons, as readily as that particular extension is which serves as a kind of support for luminous phenomena, which evidently result from vibrations of the unextended principles. Helmholtz, in his latest writings, fully adopts this doctrine of corporeal extension.

We thus see that there is no difficulty in reconciling extension with unextended forces, and the phenomena of extension with principles of action; but this is only the first part of the problem, and it becomes necessary now to ascend from these unextended forces and active principles to those more or less complex manifestations which make up the infinite universe, adorning space with imperishable variety. Let us imagine this universe filled with the greatest conceivable number of active principles, all identical, diffused uniformly throughout immensity, and consequently in a state of perfect equilibrium. All will be torpid in absolute repose, in which form without shape and force without spring will be as though they were not. Between a homogeneous, motionless substance, identical with itself throughout space at all points, and nihility, reason perceives no difference. In such a system, nothing has weight, for there is no attracting centre; heat is no more possible for it than light, since these two forms of energy are bound up with the existence of systems of unequal vibrations, of diversified media, and varying molecular arrangements. A fortiori, the phenomena of life will be incompatible with this universal unity of substance, this unchanging identity of force.

The objective existence of things, the coming into reality of phenomena, can only be conceived, therefore, as the work of a certain number of differentiations taking place in the deep of that universal energy of primal matter, which is the last result of our analysis of the world. Motion, of itself alone, is enough to explain a first attribute of that energy, namely, resistance, and its consequence, impenetrability; but this is only on the condition that this motion shall take place in various directions. Two forces urged in opposite directions, and coming to a meeting, manifestly resist each other. It is probably by collisions of this sort that those variable condensations of matter, and those heterogeneous groupings of which the world presents the spectacle, have been determined. A rotary movement, communicated to a mass without weight, can only engender concentric spheres, which gravitate toward each other in consequence of pressure by the interposing ether. The famous experiments of Plateau are decisive in this respect. That accomplished physicist introduces oil into a mixture of water and alcohol, having exactly equal density with the oil itself. He inserts a metallic strip into the midst of this mass of oil, which is free from the action of any force, and turns it about. The oil takes the form of a sphere, and, as soon as the rotation grows very rapid, breaks up, and parts into a number of smaller spheres. The celestial spheres were probably formed in the same way, and an exactly similar mechanical action produces those clear dew-drops, glittering like diamonds, on the leaves of plants.

All physical phenomena, whatever their nature, are at bottom only manifestations of one and the same primordial agent. We can no longer question this general conclusion of all modern discoveries, Sénarmont explicitly says, though it is, as yet, impossible to formulate with precision its laws and its particular conditions. If this he true, and we hope we have proved it to be so, it is plain that those conditional particularities of which Sénarmont speaks, that is to say, those diversified manifestations of the sole agent to which he alludes, can depend only on differences ín the motions which impel it. Now, the very existence of these differences necessarily implies a coördinating and regulating intelligence; but how much more extreme is the necessity for such a cause in chemical phenomena, which display such endless complications issuing from that primal energy to which every thing in the last analysis is reduced! We have seen that the variety of those stable and homogeneous energies known under the name of simple bodies, the number of which is now increased to sixty, depends on the variety of the vibrations that each one of these little worlds performs. This is the earliest intervention of a principle of difference. This principle does not merely determine the multiplication of simple bodies; it also acts in any one element with such intensity that the same element can acquire very unlike properties and attributes. What things are more heterogeneous than the diamond and charcoal, or than common phosphorus and amorphous phosphorus? Yet charcoal and diamond are chemically identical, just as the two sorts of phosphorus are. These cases of isomery, which are quite numerous, attest with the strongest evidence the excessive variability of which combinations of force are capable. When we see the same elements, combined in the same weight-proportions, produce sometimes harmless substances, sometimes terrible poisons, in one case evolve colorless or dingy products, in another brilliant hues, we become convinced that primal matter is of little consequence in comparison with the weaver who arranges its threads, and knows beforehand what the aspect of the web will be. Besides, it is not alone in the whole that the formative principle is displayed; it shows forth also in the elements, considered individually, since every one of them exhibits tendencies, elective affinities, that bear witness to some obscure instinct toward harmonious completion.

There is not only a prodigious variety in the disposition of the atoms which make up molecules, and in the arrangement of the molecules among themselves, but this arrangement is governed, besides, by admirable geometric laws. The atoms that make up molecules are not heaped and flung together at random and in disorder; they enter into composition only in fixed proportions and in fixed directions. Marc-Antoine Gauclin has proved, in a late treatise devoted entirely to these refined inquiries, the existence of some of the most important laws in the geometry of atoms. .This ingenious and persevering writer demonstrates that all chemical molecules, whether they are fitted to produce crystals or not, are formed by a symmetrical aggregation of atoms. The latter are arranged in equilibrium in two directions, perpendicular to each other, one parallel to the axis of grouping, and the other at right angles to that axis, so as always to compose a symmetrical figure. The most complicated bodies, so soon as they are brought under the law of definite proportions, and compose chemical species, are made up of molecules in which the atoms are grouped in prisms, in pyramids, in a word, in polyhedra more or less many-sided, but always of perfect regularity; so that, in this case, the differentiation is regulated with marvellous harmony.

We must now rise another degree, and pass from inorganic matter to living matter. What is it that distinguishes the latter from the former? When we make the answer depend on the results of direct experiment, nothing is easier than to establish the differential characteristics of living matter. In the first place, it is organized, that is, the anatomical elements, instead of being homogeneous and symmetrical in all points of their mass, are composed by the association of a certain number of different substances, in which carbon predominates, and which are termed immediate organic principles. Then these elements grow. At no time the same throughout, as to the substance which makes them up, they are in a state of unceasing molecular renewal, of constant metamorphosis, of simultaneous and continuous assimilation and disassimilation. Besides, the various properties these elements may exhibit, contractility, neurility, and so on, are, in consequence of the growing state that characterizes them, in so unstable a condition of equilibrium that the slightest variation in the surrounding medium is enough to occasion some change in the expression of their activity; in other words, they have excessive excitability and irritability. Such, at least, is the region within which physiology is limited; but the fact which it does not clearly enough bring out, yet the thing which is the distinctive mark of life, is the harmonious seeking for each other of all these vital monads, the disposition of biological energies to compose groups of which the end and the reason are found in what we call the individual. The differentiations of inorganic matter occur in molecules that are specific, in whatever bulk they are regarded. The differentiations of living matter take place only in individuals whose build and proportions are strictly determined. An iron bar, an iron crystal, and iron-dust, are all still iron. An organic substance fitted for life is nothing, whenever deprived of connection with an organism. It can display energy, can act; in a word, can be, so far as to be a living substance, only in virtue of taking place and rank in a certain whole, and assuming certain dependencies and connections with other more or less analogous substances. By itself it is not distinguished in essence from dead matter. It is raised to the rank and clothed with the dignity of life only from the time of its reception into that gathering of which the steps all move toward the same end, which is, the functional action of the organism, and the perpetuation of the species.

What takes place in the ovule is a miniature image of what takes place in the universe. The differentiations occurring in that mucous drop are a copy of the differentiations unfolding and expanding in the ocean of the world. It is at first a microscopic mass, homogeneous, uniform in all its parts, a collection of energies identical with each other, and the group of which does not differ perceptibly from a drop of gelatine, hanging, hardly seen, from a needle's point. Yet soon a dull motion spontaneously stirs these nearly inert atoms, and this motion is expressed by a first condensation of the ovular or vitelline substance, which is the germinating vesicle. This passes off, but at the same time other vibrations arrange the molecules of this shapeless, transparent microcosm, in the order of more complicated groups. The vitelline substance swells toward the surface, where it forms the polar globules, while at the centre it thickens to produce the vitelline nucleus. This in turn cleaves and breaks into a great number of secondary nuclei, around each of which the ovular mass distributes itself while contracting. Instead of a single cell, the ovule, which has enlarged, is now found to contain a great number. These cells, called blastodermic, then tend to arrange themselves in two layers, two leaflets placed back to back, within which the elements of the embryo appear, and little by little develop, pursuing a continuous growth, in which forces becoming forms go on incessantly producing and multiplying new forces and new forms.

Now, these separations and distributions, these orderings and classifyings, these harmonies that are set up in the ovule to compose by slow degrees the structure of the embryo, reveal a principle of differentiation analogous to that which has caused the infinite variety of things we see come forth from the confused mass of cosmic energies. There is, as many biologists had felt assured, and as Coste has had the glory of clearly demonstrating in a work which is one of the noblest scientific monuments of this age, there is a force which gives reality, direction, life, to the forms of organized matter in the egg. All eggs are alike at first. There is a complete similitude in structure and substance between those which will produce a lion and those which will produce a mouse. The forms are identical, though the future of those forms is different. It is, as Coste very well says, that "beneath that form, and beyond what the eye views, there is something which sight cannot reach, something which contains in itself the sufficient reason for all those differences now concealed under unity of configuration, and to become visible only later." This guiding idea, which Coste has brought forward, and which is admitted by all physiologists at this day, is as far from issuing out of the elementary forces of nutrition as the painter's picture is from being the creature of his palette. Yet nothing in the ovule reveals its hidden and potent virtuality. Claude Bernard, who has repeated Coste's ideas on this subject, dwells strongly on the guiding force which is in the egg, and those savants who agree with Robin in denying this force, so far as it acts on the totality of elements in the embryo, regard it at least as shared, distributed, and acting in each of these elements separately, which, at bottom, is the same thing. We see, in any case, that there is in the inmost depth, and there dates from the most rudimentary sketch of the organized being, the fixed and formed idea of those differences in choice and those sympathies in work whose system shall build up the individual. The differential coefficient of organized matter is thus of a far higher order than that of mineral matter. It is this which is a distinct and peculiar result from the impotence which experimental science betrays more plainly every day, when attempting to convert physico-chemical activities into energies of the vital order. Even could this conversion really be effected, and it is not metaphysically impossible that it might be, the existence of a spiritual principle of differentiation would be in no wise put in doubt. Hitherto, at least, such a conversion seems beyond the reach of man.

Something that yet more completely baffles his research, while commanding too his highest admiration, is the supreme degree of complexity together with refinement of that energy which is the soul. Human thought is the sum of all the forces of Nature, because it assimilates them all, while distinguishing between them, by the work that it performs upon sensations. Sensations are to thought what food is to growth. Growth is not a result of feeding; thought is not a result of sensations. Nutrition, in shaping the living organs, determines the differentiation of the concrete forms in the individual's substance; thought, in shaping general ideas, determines the differentiation of the abstract forces in the world. Thus thinking energy is as much superior to sensations as nutritive energy is to aliments. In another order of thought, we might compare the soul to a paper covered with writing in sympathetic ink. At ordinary temperatures, the letters are unseen, but they appear in fine color whenever brought near the fire. So the soul has within itself dim marks and confused shapes which sensation tints and brightens. We have seen that, in the mucous drop, a two hundred and fiftieth part of an inch through, called the ovule, the forces and tendencies of the whole nutritive and intellectual life of man lie prisoned and asleep. So, too, in that force without form or extension, which is the soul, there dwells a miniature picture of the whole universe, and, by some mystic grace of God, a dream, as it were, of that God himself. Thought consists in becoming acquainted with all the details of that picture in little, and unfolding its meaning. Thus, that which makes the whole reality of material things is form, and form, such as it is shown to us in the world, is at once a principle of differentiation and a principle of agreement; in other words, it is the work of an intelligence. Body and motion are mere phenomena. The first is only an image of substance, the last an image of action; but substance and action both are only effects of intelligent force, that is, of activity operating in view of a result. That activity, however, presents infinitely varied degrees of condensation, and we may say, with Maudsley: "One equivalent of chemical force corresponds to several equivalents of lower force; and one equivalent of vital force to several equivalents of chemical force." It is thus that modern science unties the gordian knot of the composition of matter.

 
III

A first exclusively analytical view of the world has led us to a first undeniable certainty, the existence of a principle of energy and motion. A second view of the universe, exclusively synthetic, leads us, as we have seen, to another certainty, which is the existence of a principle of differentiation and harmony. This principle is what is called spirit. Thus spirit is not substance, but it is the law of substance; it is not force, but it is the revealer of force. It is not life, but it makes life exist. It is not thought, but it is the consciousness of thought. A distinguished English savant, Carpenter, has said lately, with decisive clearness, "Spirit is the sole and single source of power." In a word, it is not reality, yet in it and by it realities are denned and differentiated, and consequently exist. Instead of saying that spirit is a property of matter, we should say that matter is a property of spirit. Of all the properties of matter, in fact, there is not one, no, not a single one, which is not bestowed on it by spirit. The true explanation, the only philosophy of Nature, is thus a kind of spiritualistic dynamism, very different from materialism, or from the mechanism of certain contemporary schools.

Materialism is false and imperfect, because it stops short at atoms, in which it localizes those properties for which atoms supply no cause, and because it neglects force and spirit, which are the only means we have, constituted as our souls are, of conceiving the activity and the appearings of beings. It is false and imperfect, because it stops half-way, and treats compound and resolvable factors as simple and irreducible ones; and because it professes to represent the world by shows, without attempting to explain the production of those shows. In a word, it sees the cause of diversity where it is not, and fails to see it where it does exist. The source of differentiations cannot be in energy itself; it must be in a principle apart from that energy, in a superior will and consciousness, of which we have doubtless only a dim and faulty idea, but as to which we can yet affirm that they have some analogy with the inner light which fills us, and which we shed forth from us, and which teaches us, by its mysterious contact with the outer world, the infinite order of the universe.

The danger from materialism is not, as we usually incline to think, corruption of morals by degradation of the soul. Too much use, for censure's sake, has been made, against this system, of the seeming ease with which its professors have convinced themselves that they cut up by the roots the very principles of morality and duty. History proves, by examples too infamous, that barbarism and license are the privilege of no philosophic sect. The real enemies of society always have been, and always will be, the ignorant and the fanatical, and it must be frankly owned that, if these exist within the pale of materialism, there are quite enough of them outside. The danger in the doctrine which reverses the natural relation of things, and asserts that spirit is a product of matter, when in truth matter is a product of spirit, this danger is of another kind; materialism is fatal to the development of the experimental sciences themselves. If, in such a case, the example of men of genius might be appealed to, how eloquent would be the testimony of the two greatest physicists of this age, Ampère and Faraday, both so earnestly convinced, so religiously possessed by the reality of the unseen world! But there are other arguments. "All that we see of the world," says Pascal, "is but an imperceptible scratch in the vast range of Nature." The claim of mere experimentalism is that it may sentence men to the fixed and stubborn contemplation of this scratch. What folly! All the history of the development of the sciences proves that important discoveries all proceed from a different feeling, which is that of a continuation of forces beyond the limits of observation, and of a harmony in relations, overruling the singularities and deformities of detached experiences. To hedge one's self within what can be computed, weighed, and demonstrated, to trust such evidence only, and bar one's self inside the prison of the senses, to hush or scorn the suggestions of the spirit, our only true light, because it is a spark of the flame that vivifies all—this is, deny it or not, the condition and the subject state of materialism. Only reason can conceive the fixity, the generality, and the universality of relations, and all savants admit that the destiny of science is to establish laws possessing these three characteristics; but to admit that is to confess by implication that partial, incoherent, imperfect, relative details must undergo a refining, a thorough conversion, in the alembic of the mind, whence they issue, with so new an aspect and meaning, that what before seemed most important becomes as mere an accessory as it is possible to be, and that which looked most ephemeral takes its place among eternal things.

The conception of atoms dates from the highest antiquity. Leucippus and Democritus, the masters of Epicurus, several centuries before the Christian era, taught that matter is composed of invisible but indestructible corpuscles, the number of which is as boundless as the vastness of the space in which they are diffused. These corpuscles are solid, endowed with shape and motion. The difference of their forms regulates the difference of their movements, and consequently of their characteristics. The conception of a principle guiding these diversities, that is, of an intelligence as the supreme cause of differentiation, is not less ancient, "All was chaotic," Anaxagoras of Clazomene said; "an intelligence intervened, and regulated all." Plato, after defining matter as an existence very hard to understand, an eternal place, never perishing, and furnishing a stage of whatever begins to be, not the subject of sense and yet perceptible, and of which we only catch glimpses as in a dream, tells us that the supreme ruler "took this mass which was whirling in unchecked and unguided movement, and made order come out of disorder." And this ordering grows real in conformity with ideas, the prototypes of things, whose totality makes the divine essence itself. The world's activities are reflections of God's thoughts. To these two fundamental notions, that of atomism and that of idealism, Aristotle added a third, that of dynamism. As he holds, indeterminate matter, in the highest degree of abstraction, is without attributes. If it tends always toward form and action, that is because it contains a principle of power, a force. Force is in Aristotle's view the principle of form. The latter relates to substance. "We have here the whole ancient philosophy regarding the world. Modern philosophy has taught us nothing different. Atomism, strengthened and widened by Descartes, and borrowed from him by Newton, is identical at bottom with that held by the teachers of Epicurus. In the same way, Leibnitz's dynamism is only a revival of Aristotle's. And, just as Descartes and Leibnitz reproduce the old Greek masters, contemporary science renews Descartes and Leibnitz.

"But what!" it will be said; "always repeating, never inventing, must that be the fixed doom of metaphysics?" Not so; these renewals contain continuous growth toward perfection. The old truth has been preserved, in its original sense, but it has been constantly illuminated and made exact in the lapse of time by happy efforts of speculative genius. Greek atomism had an immense chasm which Descartes filled by the conception of ether, the most marvellous of modern creations. Aristotle's dynamism was vague, and Leibnitz gave it precision by showing that the type and the fountain of force is and can be nothing else than spirit. He lifted the conception of force to the conception of soul. And what has been done in our days?We have computed the motion, we have detected the action, of that subtle ether, we have proved the absolute imperishableness of force, we have shown by many instances the fundamental identity of the appetitive and elective powers of chemistry and crystallography with those which psychology reveals. Here is the future of science and of metaphysics. Both will henceforth follow in their development the very course they have held to since the first day; they have never, like Penelope, destroyed yesterday's work the day after. They have pursued the same end with continuous advance, that is, the conception of invisible principles, and of the ideal essence of things. This end will remain the ever unattained goal of their ambition. The farther we shall advance, the more clearly and convincingly will they persist in defining those primal forces and elementary activities half guessed at from the very dawn of thought. Never false to themselves, they will always, at whatever point in history we appeal to them, represent the human soul unchanging in its nature, its powers, and its hopes. Let them never muse over the mournful question whether the work of the past will not vanish at some time without leaving a trace. All of it will survive, and from this confidence those who strive to increase the sum of knowledge draw their courage and consolation.

The conceptions of matter now entertained agree not only with the boldest deductions of most splendid discoveries of contemporary science, as well as with the oldest truths and the most instinctive faiths of humanity, but also with those loftier convictions, more precious and as solid, which form our moral and religious inheritance, and the crowning prerogative of our nature. The most advanced science rejects none of the traditions and objects to none of the great and lasting sentiments of past ages. On the contrary, it fixes the stamp of certainty on truths hitherto lacking adequate proofs, and rescues from the attacks of skepticism all that it coveted as its prey. No proof of the soul's immortality is so strong as that we have drawn from the necessary simplicity and eternity of all the principles of force. Nothing bears witness so powerfully to the majestic reality of a God as the spectacle of those diversities, all harmonious, which rule the infinite range of forces, and bind in unity the ordered pulses of the world. It is enough to fix the truth that the moral greatness and the intellectual dignity of a nation must always be measured by the standard of the esteem and credit it accords to high metaphysical speculations, and chiefly to such as relate to the constitution of matter. Meditation on the constitution of matter is the best method of teaching us to know spirit, and to understand that every thing must be referred to it, because from it every thing flows.—Revue des Deux Mondes.