Book I. The New Ideas On Matter

Chapter I: The Theory of Intra-Atomic Energy and of the Passing Away of Matter

1. The New Ideas on the Dissociation of Matter

The dogma of the indestructibility of matter is one of the very few which modern has received from ancient science without alteration. From the great Roman poet, Lucretius, who made it the fundamental element of his philosophical system, down to the immortal Lavoisier, who established it on bases considered eternal, this sacred dogma was never touched, and no one ever sought to question it.

We shall see in the present work how it has been attacked. Its fall was prepared by a series of earlier discoveries apparently unconnected with it: cathode rays, x-rays, emissions from radioactive bodies, etc., all have furnished the weapons destined to shake it. It received a still graver blow as soon as I had proved that phenomena at first considered peculiar to certain exceptional substances, such as uranium, were to be observed in all the substances in nature.

Facts proving that matter is capable of a dissociation fitted to lead it into forms in which it loses all its material qualities are now very numerous. Among the most important I must note the emission by all bodies of particles endowed with immense speed, capable of making the air a conductor of electricity, of passing through obstacles, and of being thrown out of their course by a magnetic field. None of the forces at present known being bale to produce such effects, particularly the emission of particles with a speed almost equaling that of light, it was evident that we here found ourselves in presence of absolutely unknown facts. Several theories were put forth in explanation of them. One only — that of the dissociation of atoms, which I advanced at the commencement of these researches — has resisted all criticism, and on this account is now almost universally adopted.

It is several years now since I proved by experiment for the first time that the phenomena observed in substances termed radioactive — such as uranium, the only substance of that kind then known — could be observed in all substances in Nature, and could only be explained by the dissociation of their atoms.

The aptitude of matter to disaggregate by emitting effluves of particles analogous to those of the cathode rays, having a speed of the same order as light, and capable of passing through material substances, is universal. The action of light on any substance, alighted lamp, chemical reactions of very different kings, an electric discharge, etc., cause these effluves to appear. Substances termed radioactive, such as uranium or radium, simply present in a high degree a phenomenon which all matter possesses to some extent.

When I formulated for the first time this generalization, though it was supported by very precise experiments, it attracted hardly any attention. In the whole world one physicists, the learned Prof. de Heen, alone grasped its import and adopted it after having verified its perfect correctness. But the experiments being too convincing to permit of a long challenge, the doctrine of the universal dissociation of matter has at last triumphed. The atmosphere is now cleared, and few physicists deny that this dissociation of matter — this radioactivity as it is now called — is a universal phenomenon as widely spread throughout the universe as heat or light. Radioactivity is now discovered in nearly everything, and in a recent paper Prof. J.J. Thomson has demonstrated its existence in most substances — water, sand, clay, brick, etc.

What becomes of matter when it dissociates? Can it be supposed that when atoms disaggregate they only divide into smaller parts, and thus form a simple dust of atoms? We shall see that nothing of the sort takes place, and that matter which dissociates dematerializes itself by passing through successive phases which gradually deprive it of its material qualities until it finally returns to the imponderable ether whence it seems to have issued.

The fact once recognized that atoms can dissociate, the question arose as to whence they obtained the immense quantity of energy necessary to launch into space particles with a speed of the same order as light.

The explanation in reality was simple enough, since it is enough to verify, as I have endeavored to show, that, far from being an inert thing only capable of giving up the energy artificially supplied to it, matter is an enormous reservoir of energy — intra-atomic energy.

But such a doctrine assailed too many fundamental scientific principles established for centuries to be at once admitted, and before accepting it various hypotheses were successively proposed. Accustomed to regard the rigid principles established for centuries to be at once admitted, and before accepting it various hypotheses were successively proposed. Accustomed to regard the first principles of thermodynamics as absolute truths, and persuaded that an isolated material system could possess no other energy than that supplied from without, the majority of physicists long persisted, and some still persist, in seeking outside it the sources of the energy manifested during the dissociation of matter. Naturally, they failed to discover it, since it is within, and not without, matter itself.

The reality of this new form of energy, of this intra-atomic energy of which I have unceasingly asserted the existence from the commencement of my researches, is in no way based on theory, but on experimental facts. Though hitherto unknown, it is the most powerful of known forces, and probably, in my opinion, the origin of most others. Its existence, so much contested at first, is more and more generally accepted at the present time.

From the experimental researches which I have detailed in various memoirs and which will be summarized in this work, the following propositions are drawn:

(1) Matter, hitherto deemed indestructible, vanishes slowly by the continuous dissociation of its component atoms.

(2) The products of the dematerialization of matter constitute substances placed by their properties between ponderable bodies and the imponderable ether — that is to say, between two worlds hitherto considered as widely separate.

(3) Matter, formerly regarded as inert and only able to give back the energy originally supplied t it, is, on the other hand, a colossal reservoir of energy — intra-atomic energy — which it can expend without borrowing anything from without.

(4) It is from this intra-atomic energy manifested during the dissociation of matter that most of the forces in the universe are derived, and notably electricity and solar heat.

(5) Force and matter are two different forms of one and the same thing. Matter represents a stable form of intra-atomic energy; heat, light, electricity, etc., represent instable forms of it.

(6) By the dissociation of atoms — that is to say, by the dematerialization of matter, the stable forms of energy termed matter is simply changed into those unstable forms known by the names of electricity, light, heat, etc.

(7) The law of evolution applicable to living beings is also applicable to simple bodies; chemical species are no more invariable than are living species.

For the examination of these several propositions a large part of this work will be reserved. Let us in this chapter take them as proved and seek at once the changes they bring about in our general conception of the mechanism of the universe. The reader will thus appreciate the interest presented by the problems to which this volume is devoted.

2. Matter and Force

The problem of the nature of matter and of force is one of those which have most exercised the sagacity of scholars and philosophers. Its complete solution has always escaped us because it really implies the knowledge, still inaccessible, of the First Cause of things. The researches I shall set forth cannot therefore allow is to completely solve this great question. They lead, however, to a conception of matter and energy far different from that in vogue at the present day.

When we study the structure of the atom, we shall arrive at the conclusion that it is an immense reservoir of energy solely constituted b y a system of imponderable elements maintained in equilibrium by the rotations, attractions and repulsions of its component parts. From this equilibrium results the material properties of bodies such as weight, form, and apparent permanence. Mater also represents movement, but the movements of its component elements are confined within a very restricted space.

This conception leads us to view matter as a variety of energy. To the known forms of energy — heat, light, etc. — there must be added another — matter, or intra-atomic energy. It is characterized by its colossal greatness and its considerable accumulation within very feeble volume.

It follows from the preceding statements that by the dissociation of atoms, one is simply giving to the variety of energy called matter a different form — such as, for example, electricity or light.

We will endeavor to give an account of the forms under which intra-atomic energy may be condensed within the atom, but the existence of the fact itself has a far greater importance than the theories it gives rise to. Without pretending to give the definition so vainly sought for if energy, we will content ourselves with stating that all phenomenality is nothing but a transformation of equilibrium. When the transformations of equilibrium are rapid, we call them electricity, heat, light, etc.; when the changes are slower, we give them the name of matter. To go beyond this we must wander into the region of hypothesis and admit, as do several physicists, that the elements of which the aggregate is represented by forces in equilibrium, are constituted by vortices formed in the midst of ether. These vortices possess an individuality, formerly supposed to be eternal, but which we know now to be but ephemeral. The individuality disappears, and the vortex dissolves in the ether as soon as the forces which maintain its existence cease to act.

The equilibria of these elements of which the aggregate constitutes an atom, may be compared to those which keep the planets in their orbits. So soon as they are disturbed, considerable energies manifest themselves, as they would were the earth or any other planet stayed in this course.

Such disturbances in planetary systems may be realized, either without apparent reason, as in very radioactive bodies when, for divers reasons, they have reached a certain degree of instability, or artificially, as in ordinary bodies when brought under the influence of various excitants — heat, light, etc. These excitants act in such cases like the spark on a mass of powder — that is to say, by freeing quantities of energy greatly in excess of the very slight cause which has determined their liberation. And as the energy condensed in the atom is immense in quantity, it results from this that to an extremely slight loss in matter there corresponds the creation of an enormous quantity of energy.

From this standpoint we may say of the various forms of energy resulting from the dissociation of material elements, such as heat, electricity, light, etc., that they represent the last stages of matter before its disappearance into the ether.

If, extending these ideas, we wish to apply them to the differences presented by the various simple bodies studied in chemistry, we should say that one simple body only differs from another by containing more or less intra-atomic energy. If we could deprive any element of a sufficient quantity of the energy it contains, we should succeed in completely transforming it.

As to the necessarily hypothetical origin of the energies condensed within the atom, we will seek for it in a phenomenon analogous to that invoked by astronomers to explain the formation of the sun, and of the energies it stores up. To their minds this formation is the necessary consequence of the condensation of the primitive nebula. If this theory be valid for the solar system, an analogous explanation is equally so for the atom.

The conceptions thus shortly summed up in no way seek to deny the existence of matter, as metaphysics has sometimes attempted to do. They simply clear away the classical duality of matter and energy. These are two identical things under two different aspects. There is no separation between matter and energy, since matter is simply a stable form of energy and nothing else.

It would, no doubt, be possible for a higher intelligence to conceive energy without substance, for there is nothing to prove that it necessarily requires a support, but such a conception cannot be attained by us. We can only understand things by fitting them into the common frame of our thoughts. The essence of energy being unknown, we are compelled to materialize it in order to enable us to reason thereon. We thus arrive — but only for the purpose of demonstration — at the following definitions: — Ether and matter represent entities of the same order. The various forms of energy (electricity, heat, light, matter, etc.) are its manifestations. They only differ in the nature and the stability of the equilibria formed in the bosom of the ether. It is by those manifestations that the universe is known to us.

More than one physicist, the illustrious Faraday especially, has endeavored to clear away the duality existing between matter and energy. Some philosophers formerly made the same attempt, by pointing out that matter was only brought home to us by the intermediary of forces acting on our senses. But all arguments of this order were considered, and rightly, as having a purely metaphysical bearing. It was objected to them that it had never been possible to transform matter into energy, and that this latter was necessary to animate the former. Scientific principles, considered assured, taught that Nature was a kind of inert reservoir incapable of possessing any energy save that previously transmitted to it. It could no more create it than a reservoir can create the liquid it holds. Everything seemed then to point out that Nature and Energy were irreducible things, as independent of one another as weight is of color. It was therefore not without reason that they were taken as belonging to two very different worlds.

There was, no doubt, some temerity in taking up anew a question seemingly abandoned forever. I have only done so because my discovery of the universal dissociation of matter taught me that the atoms of all substances can disappear without return by being transformed into energy. The transformation of matter into energy being thus demonstrated, it follows that the ancient duality of Force and Matter must disappear.

3. Consequences of this Principle of the Vanishing of Matter

The facts summed up in the preceding pages show that matter is not equal, that it constitutes an enormous reservoir of forces, and that it disappears by transforming itself into other forms of energy before returning to what it is, nothingness.

It can therefore be said that if matter cannot be created, at least can it be destroyed without return. For the classical adage, “Nothing is created, nothing is lost” (attributed to Lavoisier) must be substituted the following: — Nothing is created, but everything is lost. The elements of a substance which is burned or sought to be annihilated by any other means are transformed, but they are not lost, for the balance affords proof that their weight has not varied. The elements of atoms which are dissociated, on the contrary, are irrevocably destroyed. They lose every quality of matter, including the most fundamental of them all — weight. The balance no longer detects them. Nothing can recall them to the state of matter. They have vanished in the immensity of the ether which fills space, and they no longer form part of our universe.

The theoretical importance of these principles is considerable. At the same time when the ideas I am upholding were not yet defensible, several scholars took pains to point out how far the time-honored doctrines of the everlasting nature of matte constituted a necessary foundation for science. Thus, for instance, Herbert Spencer in one of the chapters of First Principles, headed “Indestructibility of Matter”, which he makes one of the pillars of his system, declares that, “Could it be shown, or could it with reason be supposed, that Matter, either in its aggregates or in its units, ever becomes non-existent, it would be needful either to ascertain under what conditions it becomes non-existent, or else to confess that true Science and Philosophy are impossible”. This assertion certainly seems too far-reaching. Philosophy has never found any difficulty in adapting itself to new scientific discoveries. It follows, but does not precede them.

It is not only philosophers who declare the impossibility of assailing the dogma of the indestructibility of matter. But a few years ago the learned chemist Naquet, then Professor at the Faculte de Medicine of Paris, wrote, “We have never seen the ponderable return to the imponderable. In fact, the whole science of chemistry is based on the law that such a change does not occur, for if it did so, goodbye to the equations of chemistry!”.

Evidently, if the transformation of the ponderable into the imponderable were rapid, not only must we give up the equations of chemistry, but also those of mechanics. However, from the practical point of view, none of these equations are yet in danger, for the destruction of matter takes place so slowly that it is not perceptible with the means of observation formerly employed. Losses in weight under the hundredth part of a milligram being imperceptible by the balance, chemists need not take them into account. The practical interest of the doctrine of the vanishing of matter, by reason of its transformation into energy, will only appear when means are found of accomplishing with ease the rapid dissociation of substances. When that occurs, an almost unlimited source of energy will be at man’s disposal gratis, and the face of the world will be changed. But we have not yet reached this point.

At the present time, all these questions have only a purely scientific interest, and are for the time as much lacking practical application as was electricity in the time of Volta. But this scientific interest is considerable, for these new notions prove that the only elements to which science has conceded duration and fixity are, in reality, neither fixed nor durable.

Everybody knows that it is easy to deprive matter of all its attributes, save one. Solidity, shape, color and chemical properties easily disappear. The very hardest body can be transformed into an invisible vapor. But, in spite of every one of these changes, the mass of the body as measured by its weight remains invariable, and always reappears. This invariability constituted the one fixed point in the mobile ocean of phenomena. It enabled the chemist, as well as the physicist, to follow matter through its perpetual transformations, and this is why they considered it as something mobile but eternal.

It is to this fundamental property of the invariability of mass that we had always to comeback. Philosophers and scholars long ago gave up seeking an exact definition of matter. The invariability of the mass of a given quantity of substance — that is to say, its coefficient of inertia measured by its weight, remained the sole irreducible characteristic of matter. Outside this essential notion, all we could say of matter was that it constituted the mysterious and ever-changing element whereof the worlds and the beings who inhabit them were formed.

The permanence and, therefore, the indestructibility of mass, which one recognizes throughout the changes in matter, being the only characteristic by which this great unknown conception can be grasped, its importance necessarily became preponderant. On it the edifices of chemistry and mechanics have been laboriously built up.

To this primary notion, however, it became necessary to add a second. As matter seemed incapable by itself of quitting the state of repose, recourse was had to various causes, of unknown nature, designated by the term forces, to animate it. Physics counted several which it formerly clearly distinguished from each other, but the advance in science finally welded them into one great entity, Energy, to which the privilege of immortality was likewise conceded.

And it is thus that, on the ruins of former doctrines and after a century of persistent efforts, there sprang up two sovereign powers which seemed eternal — matter as the fundamental woof of things, and energy to animate it. With the equations connecting them, modern science thought it could explain all phenomena. In its learned formulas all the secrets of the universe were enclosed. The divinities of old time were replaced by ingenious systems of differential equations.

These fundamental dogmas, the bases of modern science, the researches detailed in this work tend to destroy. If the principle of the conservation of energy — which, by-the-by, is simply a bold generalization of experiments made in very simple cases — likewise succumbs to the blows which are already attacking it, the conclusion must be arrived at that nothing in the world is eternal. The great divinities of science would also be condemned to submit to that invariable cycle which rules all things — birth, growth, decline, and death.

But if the present researches shake the very foundations of our knowledge, and in consequence our entire conception of the universe, they are far from revealing to us the secrets of the universe. They show us that the physical world, which appeared to us something very simple, governed by a small number of elementary laws, is, on the contrary, terribly complex. Notwithstanding their infinite smallness, the atoms of all substances — those, for example, of the paper on which these lines are written — now appear as true planetary systems, guided in their headlong speed by formidable forces of the laws of which we are totally ignorant.

The new routes which recent researches open out to the investigations of inquirers are yet hardly traced. It is already much to know that they exist, and that science has before it a marvelous world to explore.

Chapter II: History of the Discovery of the Dissociation of Matter and of Intra-Atomic Energy

What brought into prominence the facts and principles summarized in the preceding chapter which will be unfolded in this work? This I will now proceed to show. The genesis of a discovery is rarely spontaneous. It only appears so because the difficulties and the hesitations which most often surround its inception are generally unnoticed.

The public troubles itself very little with the way in which inventions are made, but psychologists will certainly be interested by certain sides of the following account. In fact, they will find therein valuable documents on the birth of beliefs, on the part played, even in laboratories, by suggestions and illusions, and finally on the preponderant influence of prestige considered as a principal element of demonstration.

My researches preceded, in their beginning, all those carried out on the same lines. It was, in fact, in 1896 that I caused to be published in the Comptes Rendu de l’Academie des Science, solely for the purpose of establishing priority, a short notice summing up the researches I had been making for two years, whence it resulted that light falling on bodies produced radiations capable of passing through material substances. Unable to identify these radiations with anything known, I pointed out in the same note that they must probably constitute some unknown force — an assertion to which I have often returned. To give it a name I called this radiation black light.

At the commencement of my experiments I perforce confused dissimilar things which I had to separate one after the other. In the action of light falling on the surface of a body there can be observed, in fact, two very distinct orders of phenomena:

(1) Radiations of the same family as the cathode rays. They are incapable of refraction or of polarization, and have no kinship with light. These are the radiations which to so-called radioactive substances, such as uranium, constantly emit abundantly and ordinary substances freely.

(2) Infrared radiations of great wavelength which, contrary to all that has hitherto been taught, pass through black paper, ebonite, wood, stone, and, in fact, most non-conducting substances. They are naturally capable of refraction and polarization.

It was not very easy to dissociate these various elements at a time when no one supposed that a large number of bodies, considered absolutely opaque, were, on the contrary, very transparent to the invisible infrared light, and when the announcement of the experiment of photographing a house in two minutes and in the dark-room through an opaque body would have been deemed absurd.

Without losing sight of the study of metallic radiations, I gave up some time to the examination of the properties of the infrared (1). This examination led me to the discovery of invisible luminescence, a phenomenon which had never been suspected, and enabled me to photograph objects kept in darkness for 18 months after they had seen the light.

[(1) In order not to confuse things which differ, I have reserved the term Black Light for these radiations. They will be examined in another volume devoted to the study of energy. Their properties differ considerably from those of ordinary light, not only by their invisibility, an unimportant characteristic due solely to the structure of the eye, but by absolutely special properties — that, for instance, of passing through a great number of opaque bodies and of acting in an exactly contrary direction to other radiations of the spectrum.]

These researched terminated, I was able to proceed with the study of metallic radiations.

It was at the commencement of the year 1897 that I announced in a note published in the Comptes Rendu A. S., that all bodies struck by light emitted radiation capable of tendering air a conductor of electricity (2)

[(2) This property is still the most fundamental characteristic of radioactive bodies. It was by working from this only that radium and polonium were isolated.]

A few weeks later in C.R.A.S., I also gave details of quantitative experiments serving to confirm the above, and I pointed out the analogy of the radiations emitted by all bodies under the action of light with the radiations of the cathode ray family, an analogy which no one till then had suspected.

It was at the same period that M. Becquerel published his first researches. Taking up the forgotten experiments of Niepce de Saint-Victor, and employing, like him, salts of uranium, he showed, as the latter had already done, that these salts emitted in darkness radiations able to act on photographic plates. Carrying this experiment further than his predecessor, he established the fact that the emission seemed to persist indefinitely.

Of what did these radiations consist? Still under the influence of the ideas of N. de St.-Victor, Becquerel thought at first that it was a question of what Niepce termed “stored-up light” — that is to say, a kind of invisible phosphorescence, and to prove it, he started experiments described at length in the C.R.A.S., which induced him to think that the radiations emitted by uranium were refracted, reflected, and polarized.

This point was fundamental. If the emissions of uranium could be refracted and polarized, it was evidently a question of radiations identical with light and simply forming a kind of invisible phosphorescence. If this refraction and polarization had no existence, it was a question of something totally different and quite unknown.

Not being able to fit in M. Becquerel’s experiments with my own, I repeated them with different apparatus, and arrived at the conclusion that the radiations of uranium were not in any way polarized. It then followed that we had before us not any form of light, but an absolutely new thing, constituting, as I had asserted at the beginning of my researches, a new force: “The properties of uranium were therefore only a particular case of a very general law”. It is with this last conclusion that I terminated one of my notes in the Comptes Rendu of 1897.

For nearly three years I was absolutely alone in maintaining that the radiations of uranium could not be polarized. It was only after the experiments of the Canadian physicist, Rutherford, that M.Becquerel finally recognized that he had been mistaken.


It will be considered, I think, very curious and one of the most instructive chapters in the history of science that for three years not one single physicist was to be met with in the whole world who thought of repeating — though they were extraordinarily simple — the experiments of M. Becquerel on the refraction, reflection, and polarization of the uranium rays. On the contrary, the most eminent published ingenious theories to explain this very refraction, reflection, and polarization.

It was a new version of the story of the child with the golden tooth on which the scholars of the day wrote important treatises, till one day it occurred to a skeptic to go see if the said child was really born with a golden tooth. It will be difficult, after such an example, to deny that, in scientific matters, prestige forms the essential element in conviction. We must therefore not scoff too much at those in the Middle Ages who knew no other sources of demonstration than the statements of Aristotle.

Leaving to its fate the doctrine which for several years I alone upheld, I continued my researches, enlarged the circle of my investigation, and showed that similar radiations arise, not only under the action of light, but also under very varying influences, chemical reaction especially. It became therefore more and more evident that the radiations of uranium were only, as I said from the very first, a particular case of a very general law.

This general law, which I have not ceased to study, is as follows: — Under divers influences, light, chemical action, electric action, and often even, spontaneously, the atoms of simple bodies, as well as those of compound bodies, dissociate and emit effluves of the same family as the cathode rays.

This generalization is at the present day almost universally admitted, but the preceding statement shows that it needed some courage to formulate it for the first time, Who could have supposed any relationship between the radiations of uranium and any effluves whatever, cathodic or otherwise, since nearly all physicists then admitted, on M. Becquerel’s authority, the polarization and the refraction of these rays?

When the question as to polarization was definitely settled, it took but little time to establish the correctness of the facts stated by me. But it was only after the German physicists Giesel, Meyer, and Schweidler discovered in 1899 that the emissions of radioactive bodies were, like the cathode rays, capable of deviation by a magnet, that the idea of a probable analogy between these phenomena began to spread. Several physicists then took up this study, the importance of which has increased day by day. New facts arose on all sides, and the discovery of radium by Curie gave a great impetus to these researches.

M. de Heen, Prof. of Physics at the University of Liege, and Director of the celebrated Institute of Physics in that town, was the first to accept in its entirety the generalization I had endeavored to establish. Having taken up and developed my experiments, he declared in one of is papers that in point of importance they were on a par with the discovery of x-rays. They were the origin of numerous researches on his part, which led to remarkable results. The movement once started, it had to be followed up. On all sides radioactivity was sought for, and it was discovered everywhere. The spontaneous emission is often very weak, but becomes considerable in substances placed under the influence of various excitants — light, heat, etc. All physicists are now agree in classing in the same family the cathode rays and the emissions from uranium, radium, and bodies dissociated by light, heat, and the like.

If, notwithstanding my assertions and my experiments, these analogies were not at once adopted, it is because the generalization of phenomena is at times much more difficult to discover than the facts from which this generalization flows. It is, however, from these generalizations that scientific progress is derived. “Every great advance in the sciences”, said the philosopher Jevons, “consists of a vast generalization revealing deep and subtle analogies”.

The generality of the phenomenon of the dissociation of matter would have been noticed much sooner if a number of known facts had been closely examined, but this was not done. These facts, besides, were spread over very different chapters of physics. For example, the loss of electricity occasioned by ultraviolet light had long been known, but one little thought of connecting the fact with the cathode rays. More than 50 years ago N. de St.-Victor saw that, in the dark, salts of uranium caused photographic impression for several months; but as this phenomenon did not seem connected with any known fact, it was put on one side. For a hundred years the gases of flame had been observed to discharge electrified bodies without anyone attempting to examine the cause of this phenomenon. The loss of electric charges through the influence of light had been pointed out several years before, but it was regarded as a fact peculiar to a few metals, without any suspicion of how general and important it was.

All these phenomena and many others, such as electricity and solar heat, are very dissimilar in appearance, but are the consequence of the same fact — namely, the dissociation of matter. The common link which connects them appeared clearly directly we established that the dissociation of matter and the forms of electricity which result from it are to be ranked among the most widely spread natural phenomena.

The establishment of the fact of the dissociation of matter has allowed us to penetrate into an unknown world ruled by new forces, where matter, losing its properties as matter, becomes imponderable in the balance of the chemists, passes without difficulty through obstacles, and possesses a whole series of unforeseen properties.

I have had the satisfaction of seeing, while still alive, the recognition of the facts on which I based the theories which follow. For a long time I had given up all such hope, and more than once had thought of abandoning my researched. They had, in fact, been rather badly received in France. Several of the notes sent by me to the Academy of Sciences provoked absolute storms. The majority of the members of the Section of Physics energetically protested, and the scientific press joined in the chorus. We are so hierarchized, so hypnotized and tamed by our official teaching, that the expression of independent ideas seems intolerable. Today, when my ideas have slowly filtered into the minds of physicists, it would be ungracious to complain of their criticisms or the silence of most of them towards me. Sufficient for me is it that they have been able to avail themselves of my researches. The book of nature is a romance of such passionate interest that the pleasure of spelling out a few pages repays one for the trouble this short decipherment often demands. I should certainly not have devoted over 8 years to these very costly experiments had I not at once grasped their immense philosophical interest and the profound perturbation they would finally cause to the fundamental theories of science.

With the discovery of the universal dissociation of matter is linked that of intra-atomic energy, by which I have succeed in explaining the radioactive phenomena. The second was the consequence of the first-named discovery.

The discovery of intra-atomic energy cannot, however, be quite assimilated to that of the universality of the dissociation of matter. This universal dissociation is a fact, the existence of intra-atomic energy is only an interpretation. This interpretation, besides. Was necessary, for, after having tried several hypotheses to explain the radioactive phenomena, nearly all physicists have finally fallen in with the explanation I proposed when I announced that science was face to face with a new force hitherto entirely unknown.

It may interest the reader to know how the researches which have thus been briefly recorded were received in various countries.

It was especially abroad that they created a deep impression. In France, they met with a hostility which was not, however, unanimous, as will be seen by M. Dastre, Prof. at the Sorbonne and a member of the Institute:

“In the course of 5 years a fairly long journey has been covered on the road towards the generalization of the fact of radioactivity. Starting with the idea of a property specific to uranium, we have reached the supposition of a well-nigh universal natural phenomenon.

“It is right to recall that this result was predicted with prophetic perspicacity by Gustave Le Bon. From the outset this scholar endeavored to show that the action of light, certain chemical reactions, and lastly the action of electricity, call forth the manifestation of this particular mode of energy. Far from being rare, the production of these rays is unceasing. Not a sunbeam falls on a metallic surface, not an electric spark flashes, not a discharge takes place, not a single body becomes incandescent, without the appearance of a pure or transformed cathode ray. To Gustave LeBon must be ascribed the merit of having perceived from the first the great generality of this phenomenon. Even though he has used the erroneous term of Black Light, he has nonetheless grasped the universality and the principal features of this product. He has above all set the phenomenon in its proper place by transferring it from the closet of the physicist into the grand laboratory of nature”. (Revue des Deux Mondes, 1901)

In one of the annual reviews on physical studies which he publishes annually, Prof. Lucien Poincare has very clearly summarized my researched in the following lines:

“M. Gustave Le Bon, to whom we owe numerous publications relating to the phenomena of the emission by matter of various radiations, and who was certainly one of the first to think that radioactivity is a general phenomenon of nature, supposes that under very different influences, light, chemical action, electrical action, and often even spontaneously, the atoms of simple bodies dissociate and emit effluves of the same family as cathode and x-rays; but all these manifestations would be particular aspects of an entirely new form of energy, quite distinct from electrical energy, and as widely spread throughout nature as heat. M. de Heen adopts similar ideas” (Rev. Generale des Sciences, January 1903).

I have only one fragment of a phrase to correct in the above lines. The eminent scholar says that I was “one of the first” to show that radioactivity is a universal phenomenon. This should read “the first”. It suffices to turn to the texts and to their dates of publication to be convinced of this fact. My first memoir on the radioactivity of all bodies under the action of light appeared in the Revue Scientifique of May 1897.

It is natural enough that one should not be a prophet in one’s own country. It is sufficient to be a little of one elsewhere. The importance of the results brought to light by my researches was very quickly understood abroad. Out of the different studies they called forth, I shall confine myself to reproducing a few fragments.

The first is a portion of the preamble to four articles devoted to my experiments in the English Mechanic, January-April 1903): —

“During six years Gustave Le Bon has continued his researches on certain reactions which he at fist termed Black Light. He scandalized orthodox physicists by his audacious assertion that there existed something else which had been quite unknown. However, his experiments decided other searchers to verify his assertions, and many unforeseen facts were discovered; Rutherford in America, Nedon in France, de Heen in Belgium, Lenard in Austria, Elseter and Geitel in Switzerland have successfully followed in the lines of Gustave Le Bon. Summing up today the experiments made by him for the last six years, Gustave Le Bon shows that he has discovered a new force in nature which manifests herself in all bodies. His experiments cast a vivid light on such mysterious subjects as the x-rays, radioactivity, electrical dispersion, the action of ultraviolet light, etc., Classical books are silent on all these subjects, and the most eminent electricians know not how to explain these phenomena”.

The second of the articles to which I have above alluded is one in The Academy (Dec. 6, 1902, under this heading: “New Form of Energy”:

“Hardly anything is more marked than the way in which the ideas of men of science with regard to force and matter have completely changed during the last 10 years” The atomic theory that every scrap of matter could be divided in the last resort into atoms ach in itself indivisible and combining among themselves only in fixed proportions, was then a law of scientific faith, and led to pronouncements like those of a late President of the Chemical Society, who informed his hearers in his annual allocution that the age of discovery in chemistry was closed, and that henceforth we had better devote ourselves to a thorough classification of chemical phenomena. But this prediction was no sooner uttered than it was falsified. There came before us Mr. (not then Sir William) Crookes’ discovery oF what he called ‘radiant matter’ — then Roentgen’s ray —… until now M. Gustave LeBon… assured us that these new ideas are not several things but one thing, and that they all of them point to a form of matter spread throughout the world indeed, but so inconceivably minute that it becomes not matter but force… The consequences of the final acceptance of [M. Le Bon’s] theory are fairly enormous… As for chemistry, the whole fabric will be demolished at a blow; and we shall have a tabula rasa on which we may write an entirely new system wherein matter will pass through matter, and ‘elements’ will be shown to be only differing forms of the same substance. But even this will be nothing compared with the results which will follow the bridging of the space between the material and the immaterial which M. Le Bon anticipates as the result of his discoveries, and which Sir William Crookes seems to have foreshadowed in his address to the Royal Society upon its late reception of the Prince of Wales”.

I will add to these quotations a passage from the divers articles which M. de Heen, Prof. of Physics at the University of Liege, ha kindly devoted to my researches: —

“The resounding effect produced in the world by the discovery of the x-rays is well known, a discovery which was immediately followed by one more modest in appearance, but perhaps more important in reality —, viz., that of Black Light, as the result of the researched of Gustave LeBon. This last scholar proved that bodies struck by light, especially metals, acquire the faculty of producing rays analogous to the x-rays, and discovered that this was not simply an exceptional phenomenon, but, on the contrary, one of an order of phenomena as common throughout nature as caloric, electricity, and luminous manifestations, a thesis which I also have constantly upheld from that time”.

But all this is already ancient history. The anger which my first researches provoked in France has vanished. The staffs of the laboratories formerly so hostile have welcomed with sympathetic curiosity the first editions of this work. The proof of this I have found in several articles, and especially in the review by one of the most distinguished young scholars of the Sorbonne, of which I give a few extracts: —

“It will be Dr Le Bon’s title to fame that he was the first to attack the dogma of the indestructibility of matter, and that he has destroyed it within the space of a few years. In 1986 he published a short note which will mark one of the most important dates in the history of science, for it has been the starting point of the discovery of the dissociation of matter… To the already known forms of energy, heat, light, etc., another must be added, namely matter or intra-atomic energy. The reality of this new form of energy, which Dr LeBon has made known to us, rests in no way upon theory, but is deduced from experimental fact. Although unknown till now, it is the most mighty of known forces, and may even be the origin of most of the others… The beginning of Dr Le Bon’s work produces in the reader a deep impression; one feels in it the breath of a thought of genius… Dr LeBon has been compared to Darwin. If one were bound to make a comparison, I would rather compare him to Lamarck. Lamarck was the first to have a clear idea of the evolution of living beings. Dr Le Bon was the first to recognize the possibility of the evolution of matter, and the generality of the radioactivity by which its disappearance is manifested” (Georges Bohn, Revue des Idees, 15 January 1906).

The reader will, I hope, excuse this short pleading. The repeated forgetfulness of certain physicists has compelled me to utter it. The new phenomena I have discovered have cost me too much labor, too much money, and too much annoyance for me not to try to keep a firm hold on a prize obtained with so much difficulty.