Chapter Seven

HARRIET (Emanation)

ON NOVEMBER 5, 1906, the day she was to deliver her first lecture in her new role as the Sorbonne’s first female professor, Marie went first to Sceaux, to Pierre’s grave. Here, as at the laboratory, she felt close to him. She was thinking seriously of moving to Sceaux, so she could visit the cemetery more often. Relocating outside Paris proper would doubtless be better for the girls, she reasoned, in terms of fresh air, and would also restore her father-in-law to his old familiar neighborhood, with its slower pace and wider grounds for private gardens. The extra distance from rue Cuvier would lengthen her daily commute, but she would find some way to make up the lost time.

A large and curious crowd awaited Mme. Curie in the physics amphitheater at the Sorbonne. Many were fashionably dressed and had never before found reason to be in the building. The new professor’s entrance at half past one roused an ovation better fitted to a spectacle than to a lecture. Keeping her eyes down and gripping the long table set with materials for her demonstrations, Marie could see, seated in the front row, the students from her advanced physics class at Sèvres. Although a first-time speaker usually prefaced the inaugural lecture by thanking the university and eulogizing his predecessor, she came immediately to her point.

“When we examine our recent progress in the domain of physics,” she began, “a period of time that comprises only a dozen years, we are certainly struck by the evolution of our fundamental notions regarding the nature of electricity and of matter.” Only a dozen years—the duration of her life with Pierre. “This evolution happened in part because of detailed research on the electrical conductibility of gases, and also because of the discovery and study of the phenomena of radioactivity.”

In 1894, the year she met Pierre, electricity was understood to consist of invisible “cathode rays.” These rays could be made visible as dancing streaks of light inside the elongated, evacuated glass tubes produced by British chemist Sir William Crookes. In 1895, the year she married Pierre, a Crookes tube in the lab of German physicist Wilhelm Roentgen caused a plate covered with the fluorescent material zinc sulfide to glow, though the two objects stood on opposite sides of the room. Something had jumped out of the Crookes tube to excite the zinc sulfide, and Roentgen named the something X-rays. In France, Henri Becquerel, while trying to replicate some of Roentgen’s experiments, discovered uranic rays in 1896. That same year, J. J. Thomson at the Cavendish Laboratory in Cambridge, along with his student Ernest Rutherford, demonstrated that X-rays split the air into electrically charged ions, allowing electric current to flow. Continuing alone, Rutherford showed that uranic rays did the same.

By the electrical conductivity of air, Mme. Curie had made the precise measurements that led to the discovery of two new elements, polonium and radium, plus a term to describe them: radioactive.

After Rutherford showed radioactivity to be of two types, alpha and beta, Becquerel equated the beta type with the negative ions of electric current, which had since come to be called “electrons.” The much larger alpha type carried positive charge. A radioactive atom that ejected an alpha particle instantly transformed itself into a different element. An entire section of the periodic table was thus in constant flux.

As she led her listeners through the events that had shaped her science, the audience members who were neither Sorbonne students nor Sèvriennes quickly lost the thread. Still, they sat silent and attentive, stirred by the sight of the pale figure in the black dress. When she finished speaking, Mme. Curie exited the amphitheater without waiting for another outburst of applause.

“Yesterday I gave the first class replacing my Pierre,” she wrote in her private journal. “What grief and what despair!” Addressing Pierre directly, she said: “You would have been happy to see me as a professor at the Sorbonne, and I would have done it so willingly for you.—But to do it in your place, oh my Pierre, could one dream of a thing more cruel? And how I suffered through it, and how discouraged I am.” Nevertheless she vowed to do as she had promised, motivated partly by “the desire to prove to the world and especially to myself that the one you loved so much has really some true worth.” She no longer felt lively or young. Nothing brought her joy, or even pleasure. “Tomorrow I will be 39,” she noted. “I probably have only a little time to realize at least a part of the work I have begun.”

In addition to teaching, she had stepped, for the same painful reason, into her new role as laboratory director. Her close friend and colleague André Debierne now filled her prior place as chef de travaux. The other salaried workers, the researchers, and the students were adjusting themselves accordingly to the loss of Pierre. Marie made no immediate move to recruit new personnel, but, just before the start of the fall 1906 semester, she agreed to accept a young woman who had once worked as assistant to Ernest Rutherford.

The newcomer, Canadian-born Harriet Brooks, arrived in Paris bringing several years’ experience in radioactivity research. She was thirty years old, unemployed for the first time in her life, and fresh from the breakup of her engagement to a fellow physicist at Columbia University in New York. Her first impression of the lab in the rue Cuvier gave her cause for further disappointment.

Harriet located the place with difficulty near the Jardin des Plantes, at some distance from the heart of the Sorbonne. Although the scientific equipment appeared adequate to her eye, and the supply of radioactive materials downright enviable, a wide courtyard separated the office part of the complex from the communal workspace, where nine scientists crowded together, practically cheek by jowl. Tales of the Curies’ “miserable wooden hangar” had of course reached North America, but that had been their lot before winning the Davy Medal and the Nobel Prize. One would expect the present Curie lab to occupy more convenient, more commodious quarters.

In comparison, the Macdonald Physics Building at McGill University in Montreal, where Harriet Brooks had studied and begun her research career, was large to the point of grandiose. The castle-like edifice included a turret with balconies, and its big rooms boasted the world’s finest apparatus. In fact, the acknowledged excellence of the physical plant had lured her mentor, Rutherford, away from the famed Cavendish Laboratory in England. Upon his arrival at McGill in 1898, he chose Harriet Brooks—first in her class and also president of it—as his first graduate student.

The tall, blond Rutherford was only five years older than Harriet, but he acted very much the new professor, all science and all propriety. He had a longtime sweetheart back home in his native New Zealand, Mary Newton, whom he planned to marry as soon as he could afford to support a family. Meanwhile he showed true admiration for Harriet’s ability, and assigned her a project that proved suitable for her master’s thesis: the magnetization and demagnetization of steel needles. She became the first woman to be awarded a master’s degree in physics at McGill. This achievement made her an anomaly at home as well. Of the nine Brooks children, only Harriet and her younger sister Elizabeth managed—by striving and by seizing every scholarship opportunity—to attend university.

Harriet Brooks (back row, center) and Ernest Rutherford (far right) with other physicists at McGill University, ca. 1899

Wikimedia Commons

In autumn of 1900, soon after Rutherford returned to campus from New Zealand as a newlywed, he invited Miss Brooks to assist him with experiments in the new field of radioactivity. Together they demonstrated that radium released some vapor in addition to its alpha rays. This “emanation,” as Rutherford named it, was a previously unknown gas, heavier than air, and radioactive in its own right. It seemed to be a new element, though they could hardly believe their evidence. Unlike Mme. Curie’s two new elements, which she had extracted from a complex mineral ore, their new gas came directly from radium, as though the one element had birthed the other. Moreover, the new gas went through its own subsequent change, losing its radioactivity over a period of days and leaving a solid residue on the walls of its container. The residue also proved radioactive, though its activity dissipated quickly, within minutes.

On May 23, 1901, Ernest Rutherford and Harriet Brooks reported their “new gas from radium” to the Royal Society of Canada. Mindful that their findings smacked of alchemy, they did not claim to have seen one element turn into another. Nor did they give their new gas a new name. They referred to it simply as “radium emanation”—a product distinct, though not altogether divorced, from radium.

Because McGill did not yet offer a doctoral degree in physics, Harriet continued her graduate studies at Bryn Mawr, the renowned women’s college in Pennsylvania. All through the 1901–1902 academic year, she continued to collaborate with Rutherford and to seek his counsel from afar.

“I’m afraid,” she wrote him in March 1902, “that your generosity in placing me as a collaborator where I am really nothing more than a humble assistant has rather imposed on the faculty at Bryn Mawr, for last night, they awarded me the European Fellowship.” This bounty allowed Harriet to realize the costly dream of research and study abroad. Rutherford helped her secure a place with his own mentor at the Cavendish Laboratory, physicist J. J. Thomson.

While Harriet was in England, Rutherford tapped a confident young chemist at McGill, Frederick Soddy, to wrestle the emanation with him. Their experiments affirmed Rutherford’s hunch that radium emanation was indeed a new element. In other words, by giving up an alpha particle, a radium atom changed into an atom of emanation. “This is transmutation,” Soddy is said to have blurted out in amazement. “For Mike’s sake, Soddy,” Rutherford replied in the privacy of the lab, “don’t call it transmutation. They’ll have our heads off as alchemists.”

The long-abandoned concept of transmutation, sullied by its associations with mysticism and fraud, now struck Rutherford and Soddy as a natural process with a scientific explanation. Emboldened, they made their ideas public in the summer of 1902. And although Rutherford continued to cite Harriet Brooks in his lectures and writings, only the names Rutherford and Soddy adhered to the breakthrough theory of radioactive transformation—the “new alchemy.”

AT THE CAVENDISH, Harriet found everything she needed to continue her work, except for confidence in herself. “I am afraid I am a terrible bungler in research work,” she wrote to Rutherford after several months in England; “this is so extremely interesting and I am getting along so slowly and so blunderingly with it.” She was trying to compare the emanation released by radium with a similar gas that came from thorium. “I think I shall have to give it up after this year, there are so many other people who can do so much better and in so much less time than I that I do not think my small efforts will ever be missed.” Other letters to him mentioned her “deluded moments” and “sorely muddled” work, even as J. J. Thomson commended her “very interesting results” in his own letters to Rutherford.

Harriet learned that Professor Thomson’s wife, née Rose Paget, had once been his physics student. After a dozen years of marriage, Mrs. Thomson still showed up at the laboratory every day, but only to prepare the afternoon tea and facilitate conversation between new arrivals and old hands.

Harriet went back to McGill in 1903. Under Rutherford’s aegis again, she closely observed the rise of emanation and its decay into substances that coated the chamber walls of her experimental setup or collected on wires she inserted into the chambers. She timed and measured every fluctuation in radioactivity, building up a body of work and publishing her results, till she took a position in 1904 as a physics instructor at Barnard College, the women’s arm of Columbia University in New York City.

Harriet had envisioned a teaching career since her undergraduate days, and this particular post carried the added advantage of a reunion with Bergen Davis, the Columbia physicist she had met at the Cavendish. By the summer of 1906 they were ready to announce their engagement. Harriet wanted—expected—to remain on the Barnard faculty after she married, but the dean of the college reacted to her wedding plans by requesting her immediate resignation.

Instead of resigning, Harriet argued in self-defense and against the general unfairness of the judgment: “I think also it is a duty I owe to my profession and to my sex to show that a woman has a right to the practice of her profession and cannot be condemned to abandon it merely because she marries.” Unaccustomed as she was to dissent, she apologized for questioning the administration’s authority, “but I cannot acquiesce without violating my deepest convictions of my rights.”

The dean, backed by the board of trustees, held firm. Miss Brooks could not combine marriage with her college duties because the dual roles would force one of two unsavory outcomes: either she would put her husband before her students, thereby compromising her classes, or she would put her teaching before her husband, making her the sort of wife that the college could not countenance.

Beaten, Harriet agreed to postpone the wedding indefinitely. In August she broke off the engagement. And although marriage had posed no impediment to teaching in her mind, the breakup gave her reason to resign.

“I find that it will be almost impossible for me to fulfill my engagement at Barnard for the coming year,” Harriet wrote from a summer address in the Adirondacks, “owing to the unfortunate necessity I have been under, of terminating my engagement to be married. If it is possible I should like to have my place filled and I shall spend the year in study abroad.” This resolve carried her to Paris.

Harriet’s familiarity with radioactive gases eased her entrée into the Curie lab in the fall of 1906. She partnered with André Debierne to study a third type of emanation—this one coming from actinium, the element he had discovered. Speaking French posed no real problem for her, except that in Paris courtesy required her to use the language, which had been merely optional in Montreal. The surroundings—the banks of flasks, crucibles, and glass tubing blown into custom configurations, the sprawls of gauges, wires, magnets, and miscellaneous hardware—provided familiar ground in a foreign setting. The grieving Mme. Curie, however, could not have contrasted more starkly with the booming, exuberant presence of Rutherford, whose off-key singing often resounded through the halls of the Macdonald Physics Building.

“Physically,” Harriet noted, “she is extremely frail and her two children naturally absorb some of her attention.” Yet Madame the director proved “ever ready to grapple with the difficulties and problems of those working with her, even when she was a prey to anxieties that would unnerve most women.”

Marie’s normally quiet demeanor had evolved into an almost total social isolation. In a letter to Eugénie Feytis, her former student who was now teaching physics at Sèvres, she apologized for the change in her behavior. Although her affection for Eugénie had not waned in the slightest, she said, “My life has become so difficult at this point that it’s impossible for me to devote any time to socializing. All our mutual friends will tell you that I never see them any more except for professional matters.”

She had recently assigned herself the task of redetermining the atomic weight of radium. She possessed much more material now, thanks to the ongoing reciprocal arrangement with Émile Armet de Lisle and his Sels de Radium factory. For her 1902 weighing she had made do with nine centigrams of radium chloride; this time she worked with forty decigrams (more than forty times the previous quantity). She had gained more experience, too, though the weighing remained a painstaking affair. Throughout the process the crystals of radium chloride tended to absorb water, necessitating elaborate, repeated drying procedures. In the end she was gratified to see that her 1907 result, 226.2, did not so much change as refine her earlier figure of 225±1.

She was also pleased with Harriet Brooks, and very much wanted her to stay on. Harriet had joined the lab as a travailleur libre, or independent researcher, which meant that she received no grant money or guarantee of her position. Funding was as scarce as space was tight. In the spring of 1907, however, the American industrialist Andrew Carnegie gave the Curie laboratory a $50,000 endowment to establish an annual research fellowship. Marie offered the first of these fellowships to Harriet. At the same time, Harriet heard that Rutherford was moving to the University of Manchester, where another fellowship opportunity held out hope of a new place for her at his side.

“Miss Brooks is a very good friend of my wife and myself and I should be delighted if she got the fellowship,” Rutherford told his contact at Manchester. “She’s at present working with Mme. Curie at the Sorbonne and wishes to work at research in Physics in England, if possible. She is a very able woman with an excellent knowledge of mathematical experimental Physics.” He judged her an ideal choice “on her merits, quite apart from personal considerations on my part,” and felt “quite confident she has as strong claims as any possible candidate for the position.”

Rutherford’s official letter of recommendation promoted her even more strongly: “Miss Brooks has a most excellent knowledge of theoretical and experimental Physics and is unusually well qualified to undertake research. Her work on ‘Radioactivity’ has been of great importance in the analysis of radioactive transformations and next to Mme. Curie she is the most prominent woman physicist in the department of radioactivity.” To erase any possible doubt about her capability, he added, “Miss Brooks is an original and careful worker with good experimental powers and I am confident that if appointed she would do most excellent research work in Physics.”

In May 1907 Harriet left Paris, still unsure of her future plans. “Dear Madame Curie,” she wrote from her London hotel on the last of the month, “I am sorry that I have been so long in letting you know my decision with regard to the scholarship you so kindly offered me for next year.” There had been “unexpected delays” regarding the Manchester fellowship, as well as an even more unexpected new development, which she did not explain, except to say she would not be returning to Paris. “I ask you not to keep the appointment in your laboratory open for me any longer.”

Rutherford broke the news to the Manchester fellowship committee: “Miss Brooks has just informed me that she is engaged to be married … next month.” He named her intended as a Mr. Pitcher of Montreal, “an old and persistent admirer” who had followed her to London to propose. “While personally I am sorry not to have her in Manchester, such bolts from the blue are to be expected when ladies are in question.”

Frank Henry Pitcher had risen from the position of demonstrator in Rutherford’s McGill laboratory to become general manager of the Montreal Water and Power Company. Having reconnected with Harriet shortly before she sailed for Europe, he pursued her via frequent letters over a period of months. In April he mentioned business affairs that required his attention across the Atlantic, giving him a chance to see her again. “Hurry up and discover some quicker way of decomposing or transforming radium,” his letter urged her.

They married on July 13, 1907, at the Parish Church of St. Matthew in London, and left immediately for Montreal, with Frank promising his bride that he would “try to make up to you all and more than you think you are now losing.”

In choosing him, she chose not to pursue her research. She would write up an account of her recent results for André Debierne as the final act of her professional career.

Marie’s altogether different experience of marriage had not only advanced her career instead of ending it, but positioned her to assume her singular role as female head of a laboratory. Wedded to her research partner, she had managed to incorporate love and motherhood into the fullness of a life in science, if only for a while.

“A year has passed,” she wrote on the anniversary of Pierre’s death. “I live, for your children, for your aged father. The grief is dull but always there. The burden weighs heavily on my shoulders. How sweet will it be to go to sleep and not wake up? How young my poor dear ones are! How tired I feel!”