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Perey, Marguerite Catherine


(b. Villemomble, France, 19 October 1909; d. Louveciennes, France, 13 May 1975), radioactivity, radio-chemistry, nuclear sciences.

Perey is an important figure in nuclear chemistry. Trained by Marie Curie, she discovered in 1939 the last natural radioactive element predicted by Dmitrii Mendeleev’s periodic table, francium. In 1962 she was the first woman to be elected a correspondent member to the French Académie des sciences since its founding in 1666. Neither Marie Curie nor her daughter, Irène Joliot-Curie, in spite of their respective Nobel Prizes, managed to join the institution.

Training and First Steps in Scientific Research Marguerite Catherine Perey was born on 19 October 1909 in Villemomble, near Paris. She came from a middle-class Protestant family. Her father, Louis Émile Perey, was a bank employee. He died in 1914, leaving his wife, Anne Ruissel, with their five children. For financial reasons, Marguerite, the youngest, could not attend a university but instead had to work early in her life. She studied at a private but state-recognized school for technicians, the École d’enseignement technique féminine (school for female technicians). She was first in her class upon completing her studies in 1929. As she was applying for jobs, she was given the opportunity to work at the Institut du Radium (Radium Institute) of Paris, the prestigious institution directed by Marie Curie. She started there as a chemical assistant on 1 October 1929 with a grant from the Union Minière du Haut-Katanga (Mining Union of Upper Katanga), a Belgian multinational company that controlled, during the interwar period, the market for radioactive elements and closely collaborated with Curie’s laboratory.

Perey began her career in one of the most dynamic scientific fields of the time—radioactivity—and furthermore, worked alongside one of the founders of the field. Indeed, the word radioactive had been coined by Curie in 1898 to characterize chemical substances that emitted rays similar to those of uranium. Shortly thereafter, the word was used to qualify the physical phenomena, as well as the field of research of radioactive elements and their emitted rays. A community of scientists quickly formed a network of several laboratories all over Europe that was dominated during the 1920s by four major centers: the Institut du Radium of Paris, the Cavendish Laboratory in Cambridge directed by Ernest Rutherford, the Institut für Radium-forschung (Vienna Radium Institute) at the University of Vienna directed by Stefan Meyer, and the Kaiser Wilhelm Institut für Chemie (Kaiser Wilhelm Institute of Chemistry) in Berlin, under the direction of Otto Hahn and Lise Meitner. Different ideas, concepts, and experimental practices existed regarding the application of radioactive elements, and each institution had its own approach. For instance, Rutherford’s collaborators had at first primarily concentrated on the study of physical radioactive changes and on mechanisms of disintegration of radioactive elements and their daughter products. Then, they progressively started to study atomic structure. In Berlin, researchers specialized in the identification of new radioactive elements and in the physical study of their emissions. At Curie’s laboratory, part of the work was devoted to the study of the physical and chemical properties of radioactive elements, with particular interest in the development of

different applications of radioactive elements, for example, in medical use and industrial production.

At the beginning of the 1930s, the field was transformed. A new generation of researchers included James Chadwick, Walther Bothe, and Irène and Frédéric Joliot Curie and others. They began to get new and interesting results, such as those of Enrico Fermi in Rome and of Ernest Lawrence in Berkeley, California. New research questions oriented toward the structure of atoms and particles emerged. This led to the development and the use of new laboratory techniques such as the Geiger-Müller counter in 1928—the first model was conceived before World War I—and bubble chambers such as the Wilson chamber and later particle accelerators.

Work in radioactivity, and particularly the discovery of isotopes, opened the door to a significant change in the definition of a chemical element and in the interpretation of the periodic table. Nevertheless, the traditional methods of chemistry, especially analytical methods to isolate and purify radioactive elements, still played an important role in scientists’ daily activities. When Perey arrived at Marie Curie’s laboratory, Curie was working on an element called actinium, which had been discovered in 1899 by one of her earliest collaborators, the chemist André Debierne. It was a difficult element to isolate, in part because its properties were close to those of the rare earth family of elements. Most of the chemists’ work dealt with the preparation of pure sources of the products of the disintegration of actinium, which took months, and with the magnetic spectroscopy of these daughter products’ α-radiations. Perey was in charge of the preparation of solutions containing actinium, which required patience and a great deal of precision. Under the supervision of Curie herself, she developed a great talent for the preparation of radioactive sources, and she quickly became Curie’s personal assistant. In 1934 the scientist, placing her confidence in Perey, asked her to prepare the most concentrated actiniferous sample ever prepared and to study the spectrum of actinium with Pieter Zeeman, a specialist in optical spectroscopy in Amsterdam. This was the last task Curie requested from her before her death caused by the ill effects of radiation on 4 July 1934. Perey spent four months in the Netherlands working with W. A. Lub, a chemist in Zeeman’s laboratory, measuring the spectrum of actinium for the very first time.

Discovering the Missing Element When she came back to the Institut du Radium, Perey worked under the direction of André Debierne, Curie’s successor there. She studied the spectrum of two other radioactive elements, barium and strontium, and also continued preparing sources of actinium, notably for Salomon Rosenblum, who was interested in α-spectroscopy. He was a well-known physicist working in Bellevue, near Paris, at the Laboratoire du Grand Électro-aimant (The Big Electromagnet Laboratory) with a large electromagnet and had discovered the emission of long-range α-particles by radioactive elements in 1929. Perey first published as a contributor to his work.

At the Institut du Radium, Perey was regarded as a specialist in the preparation of actinium sources. Thus, when Debierne and Irène Joliot-Curie both decided to study the actinium family, albeit for different reasons, they independently asked Perey for actinium samples. After long and repetitive work, the young technician managed to get a sample as pure as possible, about ten micrograms of actinium in a few milligrams of lanthanum solution. But during the fractional crystallizations phase, she noticed anomalies in the B-emission of actinium’s daughter products. At the end of 1938, she realized that this was due to an unknown radioactive substance formed from actinium by an α-decay. The half-life of this new element was about twenty-one minutes.

As Perey tried to study more precisely the chemical properties of this new element, she found that they perfectly matched the description of the element 87 predicted by Mendeleyev. She first called this element actinium K. It was one isotope of the only natural radioactive element not yet observed. All other elements still missing in Mendeleyev’s table happened to be artificial radioactive elements. But Perey was merely a technician without a reputation as a scientist, and so it was the French Nobel Prize–winner Jean Perrin who announced this discovery to the French Académie des sciences on 9 January 1939. This was an important event in the field of radioactivity, as several physicists in Europe and in the United States had been looking for this element for years.

A Successful Scientific Career The discovery of the new element changed Perey’s status at the Institut du Radium. She was from then on regarded as an independent researcher, free to do her own work. From 1939 to 1941 she was mobilized by the French Ministre de la défense (Ministry of Defense) to study artificial radioactivity, which had been discovered by Irène and Frédéric Joliot-Curie in 1934. She worked more precisely on B-radiations of artificial elements. Perey also continued her work on actinium and actinium K. She collaborated with Marcel Lecoin, a French researcher at the Institut du Radium, and together they showed how actinium disintegrated into actinium K.

During World War II, Perey also carried on with her university studies. André Debierne and Irène Joliot-Curie encouraged her to pass certificates in general chemistry, general physiology, and general biology at the Faculté des sciences in Paris, which enabled her to prepare a PhD thesis and to obtain a grant from the France’s Centre national de la recherche scientifique (National Center for Scientific Research). She presented her thesis at the Faculté des sciences in Paris on 21 March 1946. It dealt with the discovery of element 87. Debierne was the foreman of the jury. Irène Joliot-Curie and Pierre-Paul Grassé, a professor of zoology, were members of the board of examiners. At the end of her thesis, Perey suggested calling this element catium or francium in honor of her country, France. The name of the element was not determined until July 1947, when, in London, the International Commission of Chemistry finally adopted the latter, francium, and the symbol “Fr” for element 87.

From 1946 to 1949, Perey worked as a maître de recherche(research assistant) for the Centre national de la recherche scientifique, pursuing her research on physical and chemical properties of actinium and its daughter products. She also taught spectroscopy to researchers of the center. From then on, she was well-known and respected as a scientist and was invited to give lectures throughout Europe in Aarau, Lausanne, and Zürich, Switzerland; Liège, Belgium; and Amsterdam in the Netherlands in 1949, during the Congress of the International Commission of Chemistry. In 1950, she won the Wilde Prize of the French Académie des sciences for the discovery of francium.

On 10 March 1949, Perey was assigned a chair in nuclear chemistry at the Université de Strasbourg, France, with the charge to create a nuclear chemistry laboratory. At that time Strasbourg, being located next to the German border, was in a unique situation. During the war, it had been annexed to the German Reich and most of the researchers had taken refuge in the unoccupied part of France. The Germans had moved into the university and had created a Reichuniversität (state university) as a symbol of the Nazi’s supremacy over the rest of Europe. In particular, they had set up an Institute of Medical Research (Medizinisches Forschungsinstitut) located within the public hospital, dedicated to nuclear medical research through the collaboration with biologists, physicists, and chemists. This institute had been well financed by the Nazis. The Germans had built a Cockroft & Walton accelerator, one of the most efficient instruments used at that time in nuclear physics. For technical reasons, the Germans could not use this machine before the end of the war. As they were forced to leave Strasbourg in a hurry, they abandoned all the technical installations, including the precious accelerator.

The French medical staff, having returned to Strasbourg in 1945, discovered what the Germans had built. Some physicists, biologists, chemists, and physicians quickly realized that it might be helpful to use the accelerator to produce artificial radioactive elements for biological research. The Centre national de la recherche scientifique, directed by Frédéric Joliot-Curie, was also very interested in this accelerator; it was a promising machine at a time when French nuclear research needed significant upgrading. After long and vehement discussions between the Université de Strasbourg and the Centre national de la recherche scientifique, they formed a committee composed of members from the Faculté de médecine, the Faculté de pharmacologie and the Faculté des sciences, as well as from the Centre national de la recherche scientifique and from the Commissariat à l’énergie atomique (Atomic Energy Commission), the new French institution in charge of nuclear energy. This commission then created an interdisciplinary institute, the Institut de recherches nucléaires (Institute of Nuclear Research), at the beginning of 1948, which marked the beginning of nuclear research in Strasbourg.

The researchers from Strasbourg also decided to call upon important individuals to direct the laboratories of the institute. Thus, a chair in nuclear chemistry was offered to Perey, as she had been working on the use of radioactive labels in biology in the Parisian scientific community. With the help of her colleague, André Coche, also of the Institut du Radium of Paris, she began teaching nuclear chemistry at the Faculté des sciences of the Université de Strasbourg in September 1950, and she set up her laboratory in a building that was renovated with subsidies from the French Ministry of National Education (Ministère de l’éducation nationale). Perey’s laboratory expanded very quickly. In 1951 two young researchers joined her staff, composed of only few technicians, but a few years afterward about ten students, researchers, and lecturers were working together in the laboratory. In 1955 the number of students doubled in one year, a rise due, in part, to a teaching reform in French universities.

The research in the laboratory took two main directions. Perey studied actinium and francium’s properties and worked with biologists on biological applications of nuclear chemistry. For instance, they used radioactive elements produced by the accelerator for a series of experiences on rats, seeking to compare the way the francium and other radioactive isotopes could fix on cancerous cells to be used a radioactive tracer. Concurrently, Coche was in charge of an electronic group and was responsible for the electronic system of the laboratory. He elaborated particle detectors and studied nuclear physics such as spectroscopy. The needs of the research group continued to grow. A new research centre, made up of four laboratories—a department of nuclear physics; a department of corpuscular physics; the department of nuclear chemistry, still directed by Perey; and a department of nuclear biology—was built in the suburbs of Strasbourg and opened on 20 May 1960. Perey played an important role in the establishment of this center.

Victim of Radiation Unfortunately, Perey had to stop working a few months after the inauguration of the new center. She had been quite sick for years. Her body had been irradiated at the Institut du Radium, and she found it increasingly difficult to pursue her research because of frequent attacks of neuralgia. In 1951 she was deeply affected by the death of her mother, who was living with her in Strasbourg. From 1955 to 1957, her state improved and she was able to develop her laboratory. At the end of 1957, she had a particularly bad attack and complained about her head and shoulders. Physicians in Strasbourg did not know the cause of the attack and were not able to treat her. She, however, was persuaded that her illness was due to the effects of radiation. Her suspicions were confirmed in 1958 by Dr. Shields Warren, a physician from Boston she met at a congress in Geneva, Switzerland, on the peaceful applications of the nuclear sciences in Geneva. He had treated the Japanese victims of Hiroshima and Nagasaki and was able to measure the quantity of radioactivity in her bones. After this meeting she went to Paris for treatment and then to a health clinic in Nice.

Her medical treatments were very costly and Perey faced financial problems. She attempted in vain to have her disease recognized as an occupational one, but she did not manage to obtain an extended sick leave. Perey had first a bone cancer (which then became generalized) and the symptoms she had were less known and could be attributed to other pathologies. The physicians could clearly identify her disease only when she got a body scan in 1958 by Dr. Warren in Switzerland (this was a very recent technology and not used yet in France). They realized then that her body was completely contaminated by actinium. She remained the head of the laboratory in Strasbourg until her death. In December 1959, Gabriel Foëx, a professor at the Université de Strasbourg and a member of the French Académie des sciences, asked the academy to allocate a prize to Perey in honor of her work on francium, arguing that she had served the state and that the state was indebted to her. In 1960, Perey received the Prix Leconte (Leconte Prize) of the academy, which helped her financially for a time.

The media were greatly interested in Perey’s life. Some French popular magazines, as well as the European press, wanted to interview her and visit her new laboratory. They presented her as a new Marie Curie, as a heroine of science and victim of her research at the same time. At one point, the media coverage was so intense that Perey began refusing interviews. Although she had ceased her scientific activity, she continued to be awarded professional and public honors, such as the great medal of Paris in 1964 and the silver medal of the Université de Nice in 1969. She stayed in Nice for more than ten years, growing continually weaker, before dying of widespread cancer in a hospital in Louveciennes, near Paris, on 13 May 1975.


A complete bibliography of Perey is available at the Université Louis Pasteur of Strasbourg, France, where some professional and personal archives of Perey have been collected. The inventory of these papers and instruments is in “Fonds Marguerite Perey, répertoire numérique détaillé, 1929–1998,” available from


“Sur un élément 87 dérivé de l’actinium.” Comptes-rendus Hebdomadaires des Séances de l’Académie des Sciences 208 (1939): 97–99.

“Méthodes chimiques et physiques de marquage en biologie.”Année Biologique 24 (1948): 1–14.

“Nouvelle méthode de fractionnement des terres rares.” Journal de Chimie Physique 46 (1949): 485–493.

“Le francium: élément 87.” Bulletin de la Société Chimique de France 18 (1951): 779–785.

With André Chevallier and Charles Lausecker. “Sur la fixation, comparée de l’actinium K, du césium 134 et du rubidium 86 dans les sarcomes et les granulomes expérimentaux chez le rat.” Comptes-rendus des Séances de la Société de Biologie de France 146 (1952): 1141–1152.


Adloff, Jean-Pierre, and George B. Kauffman. “Marguerite Perey (1909–1975): A Personal Retrospective Tribute on the 30th Anniversary of Her Death.” Chemical Educator 10 (2005): 378–386.

———, and George B. Kauffman. “Francium (Atomic Number 87), the Last Discovered Natural Element.” Chemical Educator 10 (2005): 387–394.

———, and George B. Kauffman. “Triumph over Prejudice: The Election of Radiochemist Marguerite Perey (1909–1975) to the French Académie des Sciences.” Chemical Educator 10 (2005): 395–399.

Kastler, Alfred. “Notice nécrologique sur Marguerite Perey (1909–1975).” Comptes-rendus Hebdomadaires des Séances de l’Académie des Sciences, Vie Académique 280 (21 May 1975): 4–6.

Anne Fellinger
Soraya Boudia

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