Chapter Eight

ELLEN (Copper and Lithium)

IN THE LARGE garden at the new home that Marie rented in Sceaux, she found room to install a tall crossbar with a trapeze, flying rings, and a slippery cord for climbing. Ève was still too little to hoist or swing herself, but nine-year-old Irène took to gymnastics immediately, as she did to all outdoor activities, from hiking and bicycling to gardening. She had her own plot of earth now, to cultivate as she chose, with just a little guidance from Grandpère.

“My dear good Mé,” Irène wrote home to her mother in the summer of 1907 from a vacation on the Normandy coast with her Uncle Jacques’s family. “I am very happy to be at the sea and I am making some very beautiful forts in the sand and some very beautiful scratches, scrapes and grazes on my arms and legs.”

Mé and Grandpère concurred that Irène was the kind of child Pierre had been—unsuited to instruction by lecture or long hours of confinement in a classroom. The young Pierre had rambled the woods of the Paris environs and studied with tutors, including his father and older brother, until he entered university. Marie, recalling the restrictive atmosphere of her own primary education, now organized a cooperative school to meet her daughter’s perceived needs.

With the help of friends and colleagues who were also parents, she amassed a stellar faculty. Jean Perrin, formerly the Curies’ next-door neighbor on the boulevard Kellerman, volunteered to teach chemistry at his Sorbonne lab one day per week. His wife, Henriette, offered history and French in her living room. The Perrins’ two children, Francis and Aline, Irène’s longtime playmates, thus became her classmates as well, as did seven other familiar youngsters between the ages of eight and twelve. The cooperative school recalled the Flying University of Marie’s youth in that its students moved from place to place to take their classes. They traveled by train to Fonteney-aux-Roses to learn English, German, and geography from Mme. Alice Chavannes, whose husband, Edouard, was professor of Chinese at the Collège de France. Henri Mouton of the Pasteur Institute covered biology. The sculptor Jean Magrou showed the group how to model and draw, and also toured them through the collections in the Louvre. Physicist Paul Langevin, a pupil of Pierre’s who succeeded him at the industrial school and also served as Marie’s replacement at Sèvres, taught mathematics. Marie herself hosted physics class in the Curie lab on Thursday afternoons. She stressed the importance of measurement, the value of rapid mental arithmetic. She showed the children how to make and graduate a barometer, and they were amazed to see the object they had crafted actually function as intended. With it they could measure air pressure to predict changes in the weather.

“This little company which hardly knows how to read and write has permission to make manipulations, to engage in experiments, to construct apparatus and to try reactions,” marveled a gossip columnist who caught wind of the goings-on. “So far, the Sorbonne and the building in the rue Cuvier have not exploded.”

Only a few city blocks separated the Sorbonne, where the “little company” learned chemistry, from “the building in the rue Cuvier,” which housed the Curie lab. But to Marie, the different street addresses signified the gulf between the proper laboratory that Pierre had always wanted and the meager one allotted him. She considered it her duty to enlarge and improve their once-shared domain for the sake of his memory. At present the lab occupied rooms on either side of the Annex’s wide courtyard. A small, free-standing pavilion had been built in the courtyard for the Curies in 1904. Inside the pavilion, the output from Émile Armet de Lisle’s Sels de Radium factory underwent the delicate final stages of purification, by the process of fractional crystallization, to prepare radium chloride for research purposes.

Marie dutifully completed what she could of the studies interrupted by Pierre’s sudden death. Soon all of his published papers would be reissued in a collection of his complete works, edited by his two close friends and former students Charles Chéneveau and Paul Langevin. When Paul asked Marie to write a preface, she put aside the private journal in which she addressed Pierre directly and took the opportunity to extol him publicly.

“Certainly,” she wrote, “he had the power to exert a profound influence, not only through his great intelligence but also through his moral integrity and the infinite charm that he radiated, and to which it was difficult to remain indifferent.” Pierre’s reluctance to publish any but the most elegant, definitive results, she explained, limited the present volume to its six hundred pages. In what had proved to be his final year, her late husband had believed himself on the verge of attaining, at long last, the laboratory of his dreams, peopled by a team of collaborators who shared his passion for research, where he might have pursued his brilliant scientific career through an advanced old age. Alas, she concluded, “the Fates ruled otherwise, and we must bow to their inscrutable judgment.”

Marie found a new recipient—a German physicist named Hermann Starke—for the fellowship she had offered Harriet Brooks. The crowded lab could not easily accommodate additional researchers, but Marie heeded a note from a Norwegian chemist named Eyvind Bødtker promoting another potential candidate: “Miss Gleditsch,” wrote Bødtker, “is a highly educated and intelligent chemist. She would like to work with you solely out of love of science, not to obtain any kind of degree.” He assured Mme. Curie that “once you have gotten to know her, you will do anything for her, and you will not regret that you opened up your laboratory for her.” To Miss Gleditsch he offered advice and more, down to the exact wording of her letters to the director, given his familiarity with written French.

After all the arrangements were settled, Bødtker congratulated his protégée: “I am pleased to know that you, after so many years of intense work, mostly for others, will at last get out to study under better conditions than here at home. And I am confident it will turn out that you have chosen the correct branch of chemistry.”

Ellen Gleditsch, twenty-seven years old and seemingly the sole radioactivity enthusiast in all of Norway, had yet to encounter her first radioelement. She was trained as a pharmacist and supported herself assisting Bødtker in the organic chemistry laboratory at the Royal Frederick University in Kristiania (as Oslo was then known), where all her students and colleagues were men. Findings from the new world of radioactivity that reached her via foreign journals—such as the Comptes rendus and the Journal of the Chemical Society Transactions—inspired her to embrace the field as her own. She described what she knew of its brief history and the wonders of radium in an article she wrote for the popular monthly magazine For Kirke og Kultur (For Church and Culture). To engage in the new science, however, she knew she needed to seek experience abroad, whether with Rutherford in Manchester or at the Cavendish or perhaps in Vienna, where active research was also in progress, or preferably in Paris with her idol, Mme. Curie.

Once she arrived at the Curie lab in the autumn of 1907, Ellen Gleditsch quickly earned the trust of her new supervisors by dint of her deft, patient, methodical way of working—skills she had honed in her previous professional experience, and even earlier as the responsible older sister of ten younger siblings.

Ellen Gleditsch

National Library of Norway

Under the tutelage of Mme. Curie and André Debierne, Mlle. Gleditsch learned the fractional crystallization technique pioneered in the old shed. Now it was her turn to augment the lab’s supply of radium by this process, prying a jot of the much-desired radium chloride from a matrix of mostly barium chloride.

She began, as instructed, by dissolving a portion of the material in distilled water, boiling the solution, then letting it cool in a covered capsule. Radium chloride, being less soluble than barium chloride, crystallized out of solution more quickly. Beautiful yellow-orange crystals formed at the bottom of the capsule, and registered an appreciable degree of radioactivity when tested in the ionization chamber. But this small and still impure harvest was only the first step of a lengthy procedure. Next Ellen decanted the “supernatant liquid”—the portion above the crystals—and allowed part of it to evaporate, which gave her a second crop of crystals, less radioactive than the first. Then she repeated the whole process with both batches, subjecting each to dissolution, boiling, evaporating, decanting, boiling, and drying, and winding up with four portions of crystals. These she reduced to three by combining the middle two; then she put all three again through the specified series of steps. She continued dividing and repeating the treatment until she arrived at a fraction showing no radioactivity at all, which she could safely discard. Turning to the remainder, she repeated the steps afresh. As she continued in this fashion, systematically rejecting the inactive fractions in each portion, the amount of material gradually diminished in quantity but increased in radioactivity, until she had jettisoned all the barium chloride and was left with a modicum of pure radium chloride.

“I don’t understand how anyone dared to trust me with it,” Ellen later reflected. “I had between my hands a radium preparation worth 100,000 francs.”

AS ÉMILE ARMET DE LISLE had foreseen, the medical applications of radium inflated the element’s value, and rarity drove its price higher still. To meet demand, he scoured the French countryside—and other countries, too, through a network of prospectors—in search of new sources. As each candidate ore came to light, the Curie lab evaluated it and experimented with means for teasing out the radioelements from a mélange of other materials. If an ore yielded a promising result, as determined by repeated measurements of radioactivity, then the lab would instruct the factory in the specific procedure for extraction—and immediately try to streamline or otherwise improve on that procedure. But nothing could alter the harsh fact of diminishing returns in this business: A ton of rock yielded a pound, at most, of raw salts, from which Mme. Curie—and now, Ellen Gleditsch—would derive only one or two milligrams of pure radium chloride.

Ellen said little more than bonjour and bonsoir during her first few weeks at the lab, hushed by her lack of fluency in French. When she accepted Mme. Curie’s invitation to spend a Sunday afternoon en famille at her home in Sceaux, she met her best conversational match in ten-year-old Irène. In time she learned to chat just as amiably with Eugénie Feytis, “Uncle André” Debierne, the Perrins, the Langevins, and other regulars at Sunday get-togethers.

To interest Ellen and also to advance her, Marie suggested a research project regarding a new claim about transmutation from Sir William Ramsay of University College, London.

Ramsay had been knighted and awarded the 1904 Nobel Prize in Chemistry for a series of new element discoveries in the 1890s. All his finds were gases, and all of them unusual in their refusal to react with other elements. He named them for their standoffish behavior, from argon (Greek for “idle”) to xenon (“stranger”). Ramsay also showed that helium, an element first detected in the Sun’s spectrum and long thought to exist only in the Sun, occurred on Earth, too, and belonged to this same group of inert, or “noble,” gases that did not mingle with other elements.

The radioactive emanations of radium, thorium, and actinium, being both gaseous and inert, attracted Ramsay’s attention as prospective members of his noble-gases family. In a recent study, he had exposed copper—a nonradioactive element—to radium emanation. The result, he reported, was the transmutation of copper into lithium, the lightest of the metals. Other researchers doubted this outcome, even scoffed at it privately, but the only acceptable way to oppose Ramsay was to repeat what he had done and figure out what he had done wrong. This was the task Marie chose for Ellen’s initiation: to partner with her in challenging the published results of a well-established and highly decorated scientist.

“During the course of these experiments,” Ellen recalled in a memoir, “I was able to see and appreciate Marie Curie at work on a scientific problem. She was very precise in manipulations, she judged everything which resulted with a lively critical intelligence, and she evaluated the results with perfect lucidity. I saw how much she took the success of an experiment to heart. She was devastated when she realized that the introduction of the emanation hadn’t succeeded; when everything went well, she was happy, her eyes were luminous, and a smile transformed her ordinarily sad face.”

It took them several months to complete their work on the copper-lithium question. In retracing Ramsay’s steps exactly, they said they had indeed seen lithium emerge—but not for the reasons Ramsay supposed. Instead of arising from copper by transmutation, the lithium had more likely leached out of the glass vessels in his laboratory. When they substituted platinum containers for glass ones and ran through the process again, they detected no lithium in the end product. This result, a potential embarrassment for Ramsay, capped the first of Ellen’s planned two years in Paris with triumph. In the Comptes rendus of August 10, 1908, and in the pages of Le Radium, “Mlle. Gleditsch” shared a byline with “Mme. Curie.”

HAVING TAUGHT HER Sorbonne course for two years in Pierre’s place, Marie inherited his official title of university professor in 1908. Her fully credentialed recognition as first female professor set a precedent, not only in France but in all of Europe as well. Between her name and her position, she was now a magnet for aspiring radioactivists. She said yes to six new requests from independent researchers seeking places in the Curie lab.

In September, André Debierne presented her current idea for a laboratory expansion to Émile Armet de Lisle at Sels de Radium. The industrialist readily confirmed his support for her plan. He felt “very honored,” he said, and professed himself “very happy” to house a permanent extension of her research laboratory in his factory. He would put one of his staff at her disposal immediately, and provide an office for M. Debierne, in addition to lab space. “I will do everything necessary,” his letter promised, “to accommodate the new operations under your guidance.”

The association of Marie Curie’s name with his product gave Armet de Lisle an incalculable advantage in an increasingly competitive field. At the same time, the availability of his product in her laboratory enabled Mme. Curie to attempt trials, such as the Ramsay experiment, that Rutherford and other researchers had declined for want of sufficient radium. She already had another project in mind, regarding the genealogy of the radioelements.

After an atom of radium gave up an alpha particle and changed itself into an atom of gaseous emanation, the emanation gave up an alpha to become a radioactive solid provisionally named “radium A,” which in turn transformed by alpha emission into “radium B.” Over the ensuing days, weeks, months, and years, further transmutation occurred via the expulsion of alpha or beta particles, resulting more or less quickly in the creation of “radium C,” “radium D,” and “radium E,” then polonium, and lastly the stable end product, lead.

The rightful places of radium and polonium on the periodic table, which Marie had defended repeatedly, differed from the static positions of silver, say, or gold. Instead of a permanent stop, each radioelement’s slot represented a waypoint on a long road from one place to someplace else.

In the same manner that radium gave rise to other elements, it apparently arose from other elements, and ultimately from uranium. The fact that radium never occurred alone in nature, but always and only in the presence of uranium, suggested their ancestral connection. Indeed, a few researchers in the United Kingdom and the United States were actively trying to “grow” radium from uranium in their labs. They ascribed their failures so far to the presumably Methuselah-like half-life of uranium, which was believed to extend over eons. The same researchers further suspected that some number of intermediate elements stood between uranium and radium in the line of descent.

Another route to unraveling the genealogy of radium lay in the variety of uranium ores at widely separated locations around the world. If the same ratio of radium to uranium prevailed in every case, then the common proportionality would demonstrate the mother-daughter—or mother-granddaughter—relationship.

As soon as Ellen Gleditsch returned to Paris from her 1908 summer vacation with family in Norway, Marie pressed her to take up the question of the radium-uranium ratio.