WHAT DOES IT MATTER to Science if her passionate servants are rich or poor, happy or unhappy, healthy or ill? She knows that they have been created to seek and to discover, and that they will seek and find until their strength dries up at its source. It is not in a scientist’s power to struggle against his vocation: even on his days of disgust or rebellion his steps lead him inevitably back to his laboratory apparatus.
We cannot, therefore, be surprised at the brilliance of the researches Pierre and Marie carried out successfully during these difficult years. Radioactivity grew and developed, exhausting little by little the pair of physicists who had given it life.
From 1899 to 1904 the Curies published, sometimes together and sometimes separately, or sometimes in collaboration with one of their colleagues, thirty-two scientific communications. The titles of these notes are grim, and their text bristles with diagrams and formulæ which frighten the layman. Each of them, nevertheless, represents a victory. In reading the dry enumeration of the most important reports, let us think of how much curiosity, obstinacy and genius lie within them.
On the Chemical Effects of Radium Rays. Marie Curie and Pierre Curie, 1899.
On the Atomic Weight of Radiferous Barium. Marie Curie, 1900
The New Radioactive Substances and the Rays They Emit. Marie Curie and Pierre Curie, 1900.
On Induced Radioactivity Provoked by Radium Salts. Pierre Curie and André Debierne, 1901.
The Physiological Action of Radium Rays. Pierre Curie and Henri Becquerel, 1901.
On Radioactive Bodies. Marie Curie and Pierre Curie, 1901.
On the Atomic Weight of Radium. Marie Curie, 1902.
On the Absolute Measure of Time. Pierre Curie, 1902.
On Induced Radioactivity and on the Emanation of Radium. Pierre Curie, 1903.
On the Heat Spontaneously Disengaged by Radium Salts. Pierre Curie and A. Laborde, 1903.
Researches on Radioactive Substances. Marie Curie, 1903.
On the Radioactivity of Gases Freed by the Water of Thermal Springs. Pierre Curie and A. Laborde, 1904.
The Physiological Action of the Emanation of Radium. Pierre Curie, Charles Bouchard and V. Balthazard, 1904.
Radioactivity, born in France, rapidly conquered in foreign countries. From 1900 on, letters signed by the greatest names in science arrived in the Rue Lhomond from England, Germany, Austria, Denmark, all bubbling over with requests for information. The Curies thus had a continuous correspondence with Sir William Crookes, with Professors Suess and Boltzmann of Vienna, with the Danish explorer Paulsen. The “parents” of radium were lavish of explanations and technical advice to their colleagues. In several countries, research workers rushed into the search for unknown radioactive elements. They hoped to achieve new discoveries. It was a fruitful pursuit, to which we owe mesothorium, radiothorium, ionium, protactinium and radio-lead.
In 1903 two English scientists, Ramsay and Soddy, demonstrated that radium continually disengaged a small quantity of a gas, helium. This was the first known example of a transformation of atoms. A little later, still in England, Rutherford and Soddy, taking up a hypothesis considered by Marie Curie as early as 1900, published a striking Theory of Radioactive Transformation. They affirmed that radio elements, even when they seemed to be unchangeable, were in a state of spontaneous evolution: the more rapid their rate of transformation, the more powerful their “activity.”
Here we have a veritable theory of the transmutation of simple bodies, but not as the alchemists understood it [Pierre Curie was to write]. Inorganic matter must have evolved, necessarily, through the ages, and followed immutable laws.
Prodigious radium! Purified as a chloride, it appeared to be a dull white powder, which might easily be mistaken for common kitchen salt. But its properties, better and better known, seemed stupefying. Its radiation, by which it had become known to the Curies, passed all expectation in intensity; it proved to be two million times stronger than that of uranium. Science had already analyzed and dissected it, subdividing the rays into three different kinds, which traversed the hardest and most opaque matter—undergoing modification, of course. Only a thick screen of lead proved to be able to stop the insidious rays in their invisible flight.
Radium had its shadow, its ghost: it spontaneously produced a singular gaseous substance, the emanation of radium, which was also active and destroyed itself clearly even when enclosed in a glass tube, according to rigorous law. Its presence was to be proved in the waters of numerous thermal springs.
Another defiance of the theories which seemed the immovable basis of physics was that radium spontaneously gave off heat. In one hour it produced a quantity of heat capable of melting its own weight of ice. If it was protected against external cold it grew warmer, and its temperature could go up as much as ten degrees centigrade or more above that of the surrounding atmosphere.
What could it not do? It made an impression on photographic plates through black paper; it made the atmosphere a conductor of electricity and thus discharged electroscopes at a distance; it colored the glass receivers which had the honor of containing it with mauve and violet, it corroded and, little by little, reduced to powder the paper or the cottonwool in which it was wrapped.
We have already seen that it was luminous.
This luminosity cannot be seen by daylight [Marie wrote] but it can be easily seen in half darkness. The light emitted can be strong enough to read by, using a little of the product for light in darkness …
Radium was not content with this marvelous gift: it also gave phosphorescence to a large number of bodies incapable of emitting light by their own means.
Thus with the diamond:
The diamond is made phosphorescent by the action of radium and can so be distinguished from imitations in paste, which have very weak luminosity.
And, finally, the radiation of radium was “contagious”—contagious like a persistent scent or like a disease. It was impossible for an object, a plant, an animal or a person to be left near a tube of radium without immediately acquiring a notable “activity” which a sensitive apparatus could detect. This contagion, which interfered with the results of precise experiments, was a daily enemy to Pierre and Marie Curie.
When one studies strongly radioactive substances [Marie writes], special precautions must be taken if one wishes to be able to continue taking delicate measurements. The various objects used in a chemical laboratory, and those which serve for experiments in physics, all become radioactive in a short time and act upon photographic plates through black paper. Dust, the air of the room, and one’s clothes, all become radioactive. The air in the room is a conductor. In the laboratory where we work the evil has reached an acute stage, and we can no longer have any apparatus completely isolated.
Long after the death of the Curies, their working notebooks were to reveal this mysterious “activity,” so that after thirty or forty years the “living activity” would still affect measuring apparatus
Radioactivity, generation of heat, production of helium gas and emanation, spontaneous self-destruction—how far we had traveled from the old theories on inert matter, on the immovable atom! Not more than five years before, scientists had believed our universe to be composed of defined substances, elements fixed forever. Now it was seen that with every second of passing time radium particles were expelling atoms of helium gas from themselves and were hurling them forth with enormous force. The residue of this tiny, terrifying explosion, which Marie was to call “the cataclysm of atomic transformation,” was a gaseous atom of emanation which, itself, was transformed into another radioactive body which was transformed in its turn. Thus the radio elements formed strange and cruel families in which each member was created by the spontaneous transformation of the mother substance: radium was a “descendant” of uranium, polonium a descendant of radium. These bodies, created at every instant, destroyed themselves according to eternal laws: each radio element lost half its substance in a time which was always the same, which was to be called its “period.” To diminish itself by one half, uranium required several thousand million years, radium sixteen hundred years, the emanation of radium four days, and the “descendants” of emanation only a few seconds.
Motionless in appearance, matter contained births, collisions, murders and suicides. It contained dramas subjected to implacable fatality: it contained life and death.
Such were the facts which the discovery of radioactivity revealed. Philosophers had only to begin their philosophy all over again and physicists their physics.
The last and most moving miracle was that radium could do something for the happiness of human beings. It was to become their ally against an atrocious disease, cancer.
The German scientists Walkhoff and Giesel announced in 1900 that the new substance had certain physiological effects; Pierre Curie at once applied the technique which seemed to him most practical. Indifferent to danger, he exposed his arm to the action of radium. To his joy, a lesion appeared. He watched over it, followed its evolution and, in a report to the Academy, phlegmatically described the symptoms observed.
After the action of the rays, the skin became red over a surface of six square centimeters; the appearance was that of a burn, but the skin was not painful, or barely so. At the end of several days the redness, without growing larger, began to increase in intensity; on the twentieth day it formed scabs, and then a wound which was dressed with bandages; on the forty-second day the epidermis began to form again on the edges, working toward the center, and fifty-two days after the action of the rays there is still a surface of one square centimeter in the condition of a wound, which assumes a grayish appearance indicating deeper mortification.
I may add that Mme Curie, in carrying a few centigrams of very active matter in a little sealed tube, received analogous burns, even though the little tube was enclosed in a thin metallic box. One action lasting less than half an hour, in particular, produced a red spot at the end of fifteen days, which left a blister similar to that of a superficial burn and took fifteen more days to cure.
These facts show that the duration of the evolution of the changes varies with the intensity of the active rays and with the duration of the action which originally excites them.
Besides these lively effects, we have had various effects on our hands during researches made with very active products. The hands have a general tendency toward desquamation; the extremities of the fingers which have held tubes or capsules containing very active products become hard and sometimes very painful; with one of us, the inflammation of the extremities of the fingers lasted about a fortnight and ended by the scaling of the skin, but their painful sensitiveness had not yet completely disappeared at the end of two months.
Henri Becquerel, carrying a glass tube of radium in the pocket of his waistcoat, was also burned, but not because he had wished to be. Astonished and angry, he hurried to the Curies to tell them about his mishap and the exploits of their terrible child. He declared, by way of conclusion:
“I love this radium, but I’ve got a grudge against it!”
Then he hastened to draw up the results of the involuntary experiment, which appeared in the Proceedings of June 3, 1901, alongside Pierre’s observations.
Struck by this surprising power of the rays, Pierre studied the action of radium on animals. He collaborated with two medical men of high rank, Professors Bouchard and Balthazard. Their conviction was soon formed: by destroying diseased cells, radium cured growths, tumors and certain forms of cancer. This therapeutic method was to be called Curietherapy. French practitioners (Daulos, Wickam, Dominici, Degrais, and others) made the first treatments of diseased persons with success, employing tubes of emanation of radium lent by Marie and Pierre Curie.
The action of radium on the skin was studied by Dr Daulos at St Louis’ Hospital [Marie Curie was to write]. Radium gave encouraging results from this point of view: the epidermis, partially destroyed by its action, formed again in a healthy state.
Radium was useful—magnificently useful.
The immediate consequence of such revelations can be guessed. The extraction of the new element no longer had merely experimental interest. It had become indispensable, salutary. A radium industry was about to be born.
Pierre and Marie watched over the beginning of this industry, which could not have been created without their advice. They prepared by their own hands the first gram of radium that saw the light—by the hands of Marie, chiefly—in treating eight tons of pitchblende residue at the shed behind the School of Physics, according to a process of their invention. Little by little the magic properties of radium excited other imaginations, and the couple found practical help in organizing production on a vast scale.
The wholesale treatment of ores was begun under the direction of André Debierne at the Central Chemical Products Company, which consented to effect the operation without making a profit. In 1902 the Academy of Science awarded the Curies a credit of 20,000 francs “for the extraction of radioactive matter.” They began at once to purify five tons of ore.
In 1904 a French industrialist who was intelligent and bold, Armet de Lisle, had the idea of founding a factory to make radium and to furnish it to doctors for the treatment of malignant tumors. He offered Pierre and Marie a laboratory attached to this factory, where the scientists could successfully carry out work which the narrow limits of their wooden shed made impracticable. The Curies found collaborators such as F. Haudepin and Jacques Danne, to whom Armet de Lisle confided the extraction of the precious substance.
Marie was never to be separated from her first gram of radium, which she bequeathed to her laboratory. It never had, and was never to have, a value other than that of her tenacious effort. When the shed had been knocked down by the wrecker’s ax and Mme Curie was no more, this gram of radium was to remain as the shining symbol of a great work and of the heroic period of two existences.
The grams which followed had a different value: a value in gold. Radium, regularly put on sale, became one of the dearest substances in the world: during these first years, it was estimated at 750,000 gold francs* by gram.
Such an aristocratic material was worth commenting upon: in January 1905 appeared the first number of a review, Radium, which was to treat exclusively of radioactive products.
Radium had acquired a commercial personality. It had its market value and its press. On the letterheads of the Armet de Lisle factory was soon to be read, in big letters:
RADIUM SALTS—RADIOACTIVE SUBSTANCES.
Telegraphic address: RADIUM, NOGENT–SUR–MARNE.
If the fruitful work of scientists in several countries, the creation of an industry, and the first trials of a wonderful treatment for disease had been possible to accomplish, it was because a blonde young woman, carried away by her passionate curiosity, had chosen in 1897 to study Becquerel’s rays as the subject of her thesis. It was because she had been able to guess at the presence of a new substance and, joining her efforts to those of her husband, to prove the existence of this substance. It was because she had succeeded in isolating pure radium.
We see this young woman on June 25, 1903, before the blackboard in a little hall of the Sorbonne, the “students’ hall,” reached by a twisting hidden staircase. Five years had gone by since Marie had attacked the subject of her thesis. Involved in the whirlwind of an immense discovery, she had put off her doctor’s examination again and again, as she could not find the necessary time to assemble her material. Today she was presenting herself before her judges.
According to custom, she had sent the examiners, MM. Lippmann, Bouty and Moissan, the text of the work she was submitting for their approval: “Researches on Radioactive Substances, by Madame Sklodovska Curie.” And—incredible event!—she had bought herself a new dress, all black, in “silk and wool.” To be exact, Bronya, who had come to Paris for the presentation of the thesis, had made Marie ashamed of her shiny clothes and had carried her off by force to a shop. It was Bronya who had debated with the saleswoman, fingered the stuffs, and decided on the alterations, without paying any attention to the sulky, absent-minded face of her younger sister.
Did the two sisters remember that it was exactly twenty years since, in the radiant month of June 1883, Bronya had dressed Marie for another occasion? It was a solemn morning: little Manyusya, dressed in black, was to receive from the hands of a Russian official the gold medal of the Gymnasium in the Krakovsky Boulevard.…
Mme Curie was standing very straight. On her pale face and rounded brow, completely bared by her fair hair brushed back in a crest, a few lines marked the traces of the battle she had fought and won. Physicists and chemists were crowded into the sun-filled room where more chairs had had to be added: the exceptional interest of the researches to be spoken of here had attracted men of science.
Old Dr Curie, Pierre Curie and Bronya had taken their places at the back of the room, squeezed in between students. Near them could be seen a group of young girls fresh and chattering: they were Sèvres girls, pupils of Marie, who had come to applaud their professor.
The three examiners in evening dress sat behind a long oak table. They took turns in asking questions of the candidate. To M. Bouty, to Lippmann, her first master, with subtle inspired features, and to M. Moissan, whose impressive beard seemed to go on forever, Marie answered in a gentle voice. Sometimes she traced the design of an apparatus or the signs of a fundamental formula on the blackboard with a piece of chalk. She explained the results of her research in sentences of technical dryness, with dull adjectives. But in the brains of the physicists around her, young and old, pontiffs and disciples, a “transmutation” of another order took place: Marie’s cold words changed into a dazzling and exciting picture: that of one of the greatest discoveries of the century.
Scientists disapprove of eloquence and comments. In conferring on Marie Curie the rank of doctor, the judges gathered at the Faculty of Science were to use in their turn words without brilliance, to which their extreme simplicity, as one rereads them thirty years later, gives deep emotional value.
M. Lippmann, the president, pronounced the sacred formula:
“The University of Paris accords you the title of doctor of physical science, with the mention ‘très honorable.’ ”
When the unobtrusive applause of the audience had been stilled, he simply added in friendship, with the timid voice of an old scholar:
“And in the name of the jury, madame, I wish to express to you all our congratulations.”
These austere examinations, these serious and modest ceremonies, taking place in exactly the same way for the genius of research and for the conscientious worker, are not fit subjects for irony. They have their style and their greatness.
Sometime before the presentation of the thesis, and before the industrial treatment of radium had been developed in France and abroad, Pierre and Marie Curie took a decision to which they did not attach special importance, but which was to have a great influence over the rest of their lives.
By purifying pitchblende and isolating radium Marie had invented a technique and created a process for manufacture.
Since the therapeutic effects of radium had become known, radioactive ores were sought for everywhere. Plans for exploitation had been made in several countries, particularly in Belgium and in America. But these factories could only produce the “fabulous metal” if their engineers knew the secret of the delicate operations involved in preparing pure radium.
Pierre explained these things to his wife one Sunday morning in the little house in the Boulevard Kellermann. The postman had just brought a letter from the United States. The scientist had read it attentively, had folded it up again and placed it on his desk.
“We must speak a little about our radium,” he said in peaceful tones. “The industry is going to be greatly extended; that is certain now. The recent cures of malignant tumors have been conclusive; in a few years the whole world will be wanting radium. Just now, in fact, this letter has come in from Buffalo—some technicians who want to exploit radium in America ask me to give them information.”
“Well, then?” Marie said, taking no vivid interest in the conversation.
“Well, then, we have a choice between two solutions. We can describe the results of our research without reserve, including the processes of purification …”
Marie made a mechanical gesture of approval and murmured:
“Yes, naturally.”
“Or else,” Pierre went on, “we can consider ourselves to be the proprietors, the ‘inventors’ of radium. In this case it would be necessary, before publishing exactly how you worked to treat pitchblende, to patent the technique and assure ourselves in that way of rights over the manufacture of radium throughout the world.”
He made an effort to clarify the position in objective fashion. It was not his fault if, in pronouncing words with which he was only slightly familiar, such as “patent” and “assure ourselves of the rights,” his voice had a hardly perceptible inflection of scorn.
Marie reflected a few seconds. Then she said:
“It is impossible. It would be contrary to the scientific spirit.”
Pierre’s serious face lightened. To settle his conscience, he dwelt upon it.
“I think so too.… But I do not want this decision to be taken lightly. Our life is hard—and it threatens to be hard forever. We have a daughter; perhaps we may have other children. For them, and for us, this patent would represent a great deal of money, a fortune. It would be comfort made certain, and the suppression of drudgery.…”
He mentioned, too, with a little laugh, the only thing which it was cruel for him to give up:
“We could have a fine laboratory too.”
Marie’s gaze grew fixed. She steadily considered this idea of gain, of material compensation. Almost at once she rejected it.
“Physicists always publish their researches completely. If our discovery has a commercial future, that is an accident by which we must not profit. And radium is going to be of use in treating disease.… It seems to me impossible to take advantage of that.”
She made no attempt to convince her husband; she guessed that he had spoken of the patent only out of scruple. The words she pronounced with complete assurance expressed the feelings of both of them, their infallible conception of the scientist’s role.
In the silence Pierre repeated, like an echo, Marie’s phrase:
“No. It would be contrary to the scientific spirit.”
He was appeased. He added, as if settling a question of no importance:
“I shall write tonight, then, to the American engineers, and give them the information they ask for.”
In agreement with me [Marie was to write twenty years later] Pierre Curie decided to take no material profit from our discovery: in consequence we took out no patent and we have published the results of our research without reserve, as well as the processes of preparation of radium. Moreover, we gave interested persons all the information they requested. This was a great benefit to the radium industry, which was enabled to develop in full liberty, first in France and then abroad, furnishing to scientists and doctors the products they needed. As a matter of fact this industry is still using today, almost without modification, the processes which we pointed out.
The “Buffalo Society of Natural Science” has offered me, as a souvenir, a publication on the development of the radium industry in the United States, accompanied by photographic reproductions of the letters in which Pierre Curie replied most fully to the questions asked by the American engineers [1902 and 1903].
A quarter of an hour after this little Sunday-morning talk, Pierre and Marie passed the Gentilly gate on their beloved bicycles, and, pedaling at a good pace, headed for the woods of Clamart.
They had chosen forever between poverty and fortune. In the evening they came back exhausted, their arms filled with leaves and bunches of field flowers.
* $150,000.