Perey, Marguerite (1909–1975)

French nuclear chemist and physicist who discovered Francium, the 87th element in the periodic table, in 1938. Born Marguerite Catherine Perey on October 19, 1909, in Villemomble, France; died in Louveciennes, France, on May 14, 1975; youngest of five children of an industrialist; never married.

Marguerite Perey began her scientific career as the personal assistant and confidante of Marie Curie . A meticulous, determined researcher, in 1938 Perey discovered the last element to be found in nature (i.e., without atomic bombardment) and the first to be discovered in two decades, the long-sought 87th element. In 1962, Perey would become the first woman to be admitted to the French Academy of Sciences.

She was born in 1909 into a financially affluent family in Villemomble, a small suburb northeast of Paris. The outbreak of World War I in 1914 revealed the world's fragile nature to the young Marguerite, who lost her father at the outset of the conflict. She was educated at the École d'Enseignement Technique Féminine, a private but state-recognized school for technicians. After being awarded her Diplôme d'Etat de Chimiste in 1929, she immediately joined the world-famous Paris Institut du Radium, whose director was the illustrious Marie Curie. Madame Curie quickly became aware of the intelligence, skill, and eagerness of her young laboratory assistant, and she chose Perey to be her préparateur (personal assistant) and confidante.

When Perey began working at the Institut du Radium, her first assigned task was the purification of actinium, a radioactive element discovered in 1899 by André Louis Debierne (1874–1949). The actinide series had not been investigated as thoroughly as had the other two naturally radioactive families, the radium and thorium series. In the 1930s, little was known about actinium, and even its half-life was uncertain, with estimates ranging from 7 to 22 years. Laboratory investigations of actinium represented a daunting challenge, because it is much rarer than the accompanying rare earth elements, from which it is separated with great difficulty. Determined to overcome the challenges, Perey spent countless hours in the laboratory. Within a few years, most other scientists in the field of radiochemistry joined in recognizing her unusual talents.

By the mid-1930s, Perey had succeeded in preparing the most intense source of actinium ever available. Even then—at only ten millicuries concentrated in a few milligrams of lanthanum oxide—it was minuscule compared to most other laboratory samples. The work she did was not only demanding, but over the decades would expose Perey to dangerous dosages of radioactivity.

The death of Madame Curie in 1934 was a severe blow to Perey, who lost both a patron and a revered scientific mentor. Perey would later recall with considerable emotion the five formative years she had spent in close, nearly daily, contact with Madame Curie. Following Curie's death, André Debierne became the Institut's director. Both he and Curie's daughter, Irène Joliot-Curie , asked Perey to continue her research on the still little-understood properties of actinium, hoping that she would be able to determine its precise half-life.

During the autumn of 1938, Perey observed an anomaly in the beta rays emitted by an actinium sample that had been separated from all of its descendants. With her customary thoroughness, she was able at this time to observe an emission phenomenon that had remained undetected for four decades by a number of earlier and less skillful radiochemists. After numerous painstaking tests, in January 1939 Perey concluded that she had discovered the long-sought element theorized as part of the periodic table, the vacant number 87, eka-caesium. Amazingly, this discovery had not been made by an eminent professor but rather by a modest 29-year-old technician lacking a university degree.

Perey's findings caused considerable disquiet in the Curie laboratory. Even though both Debierne and Joliot-Curie had been kept informed separately of the progress of Perey's investigations, when Joliot-Curie told Debierne of Perey's success at discovering eka-caesium, he flew into a jealous rage over her breakthrough, because he felt he had been equally involved in the work. Possibly as a result of this tension, neither he nor Joliot-Curie were listed as a coauthor in the published note in which Perey reported her discovery. Initially called Actinium K, this element—the most unstable of elements numbered 102 or below in the periodic table as well as the heaviest alkali metal—was renamed Francium in 1945 in honor of Perey's native country. She had briefly considered naming the new element catium (from cation, the term describing positively charged ions) but changed her mind when some of her scientific colleagues suggested that this sounded too much like "cat."

Perey next devoted her energy to the considerable challenge of investigating the chemical and nuclear properties of the newly discovered, highly elusive element. Encouraged by both Debierne and Joliot-Curie, she also began her university studies during the troubled years of World War II, simultaneously attending the Sorbonne and receiving her secondary school licence diploma. With this, she became qualified to defend a thesis at the Sorbonne for a Docteur ès Sciences Physiques degree, which she successfully accomplished on March 2, 1946.

Over the next decades, Perey accepted many professional responsibilities and was the recipient of many honors. She worked closely with France's National Center of Scientific Research (CNRS), as well as with the International Union of Pure and Applied Chemistry. Among her awards were the Grand Prix de la Ville de Paris, the Lavoisier Prize of the Académie des Sciences, the Silver Medal of the Société Chimique de France, Officier of the Légion d'Honneur, and Commandeur of the Ordre Nationale du Mérite and of the Order of Palmes Académiques. After being twice awarded the lauréat of France's Académie des Sciences (1950 and 1960), she was elected on March 12, 1962, as the first woman to be a corresponding member of that prestigious body, which had been founded in 1666 during the reign of Louis XIV.

In 1949, Perey was called to occupy a newly created professorial chair of nuclear chemistry at the University of Strasbourg, the only such chair outside of Paris. Here she organized an ambitious program of instruction and research in radiochemistry and nuclear chemistry. Her own research interests included the fixation of Francium on healthy and cancerous organs. In 1958, Perey became director of a significant research facility located at Strasbourg-Cronenbourg which had grown out of a small laboratory she established in the early 1950s. There, various areas within the field of nuclear chemistry were investigated. Very likely as a result of a lifetime of exposure to radiation, she was diagnosed with cancer in the early 1960s. After a long, valiant fight against the illness, Perey died at Louveciennes, France, on May 14, 1975.

sources:

Kauffman, George B., and Jean-Pierre Adloff. "Marguerite Perey and the Discovery of Francium," in Education in Chemistry. Vol. 26, no. 5. September 1989, pp. 135–137.

Keller, Cornelius. "Francium," in Chemiker-Zeitung. Vol. 101, no. 11. November 1977, pp. 482–486.

McGrayne, Sharon Bertsch. Nobel Prize Women in Science. Revised ed. Secaucus, NJ: Citadel, 1998.

Milite, George A. "Marguerite Perey 1909–1975," in Emily J. McMurray, et al., eds., Notable Twentieth-Century Scientists. Vol. 3. Detroit, MI: Gale Research, 1995–98, p. 1567.

Rayner-Canham, M.F., and G.W. Rayner-Canham. "Pioneer Women in Nuclear Science," in American Journal of Physics. Vol. 58, no. 11. November 1990, pp. 1036–1043.

Venetskii, S. "Francium," in The Metallurgist. Vol. 22, no. 1–2, 1978, pp. 61–65.

Yount, Lisa. A to Z of Women in Science and Math. NY: Facts on File, 1999.

John Haag , Associate Professor of History, University of Georgia, Athens, Georgia