The Elements of Marie Curie

Dava Sobel's nonfiction work traces the life and scientific career of Marie Curie while highlighting the 45 women who trained in her laboratory and went on to reshape the landscape of science in Europe and beyond.

Born Marya Salomea Sklodowska in 1867 in Russian-occupied Warsaw, Marie grew up in a family devoted to education and Polish nationalism. Her sister Zofia died of typhus in 1876, and her mother died of tuberculosis in 1878. Despite financial hardship, Marie excelled at school, finishing first in her class in 1883. She devised a plan with her older sister Bronya: Marie would work as a governess to fund Bronya's medical studies in Paris, and Bronya would later support Marie at the Sorbonne. During her years as a governess, Marie pursued self-education and attended the clandestine "Flying University," a network of secret classes offering higher education to women in defiance of Russian authorities.

In November 1891, Marie enrolled in the Faculté des sciences, the Sorbonne's science faculty, as one of only 23 women among nearly 2,000 men. She placed first in physical sciences in 1893 and secured a commission to study the magnetic properties of steel. This work led to her meeting Pierre Curie, a physicist known for his research on magnetism and his co-discovery of piezoelectricity, the production of electric current by applying pressure to certain crystals. They married in July 1895, and their daughter Irène was born in September 1897.

For her doctoral research, Marie investigated "uranic rays," radioactive emissions from uranium, discovered by physicist Henri Becquerel in 1896. Using an ionization chamber, a device that measures ionized air to detect radiation, she established that the emission of rays was an intrinsic atomic property of uranium. When she found that pitchblende, a uranium-rich mineral ore, registered more activity than pure uranium, she suspected the ore harbored an unknown, highly radioactive element. Pierre abandoned his own research to join her. In July 1898 they announced the discovery of "polonium," named for Marie's native country; Marie introduced the term "radio-active." By December they had identified a second new element, "radium," with activity a thousandfold that of uranium.

The scientific community remained skeptical, since the Curies had only traces of their new elements. Marie spent 1899 to 1902 processing tons of pitchblende waste in a leaky wooden shed. André Debierne, a young chemist, joined their team and discovered a third radioelement, actinium. In March 1902, Marie obtained enough radium chloride to determine radium's atomic weight, establishing it as a genuine element. She defended her doctoral dissertation in June 1903, becoming the first woman in France to receive a PhD in physics. That November, the Curies shared the Nobel Prize in Physics with Becquerel; Pierre had intervened to ensure Marie's inclusion after learning she might be excluded.

The Curies' second daughter, Ève, was born in December 1904. On April 19, 1906, Pierre was killed when a horse-drawn wagon struck him on a Paris street. Marie accepted the Sorbonne's offer to succeed him as professor and laboratory director.

As director, Marie attracted talented women from across Europe. Canadian physicist Harriet Brooks, who had co-discovered radium emanation (later named radon) with Ernest Rutherford, joined in 1906 but left after becoming engaged, ending her scientific career. Norwegian chemist Ellen Gleditsch arrived in 1907 and became one of Marie's most accomplished protégées, mastering fractional crystallization, a technique of repeated crystallizing steps used to separate similar substances, and collaborating with Marie to disprove a transmutation claim by Nobel laureate Sir William Ramsay. Marie officially became the first female professor in all of Europe in 1908.

In early 1910, Marie and Debierne isolated pure metallic radium. That year she began a secret affair with physicist Paul Langevin, a former student of Pierre's. In January 1911, she narrowly lost election to the Académie des Sciences, France's national academy of sciences, trailing by one vote on the first ballot before her opponent secured a majority on the second. That November, newspapers exposed her affair with Langevin. Days later she learned she had won the 1911 Nobel Prize in Chemistry for discovering radium and polonium. Despite pressure to stay away, she attended the Stockholm ceremony, declaring there was no connection between her scientific work and her private life.

Marie collapsed with a kidney ailment in late December 1911 and spent months convalescing. She deposited her international radium standard at the Bureau International des Poids et Mesures, the international bureau that maintains measurement standards, in February 1913. By this time, the concept of "isotopes," chemically identical forms of the same element differing in atomic weight, had resolved overcrowding on the periodic table.

When World War I broke out in August 1914, Marie dedicated herself to military radiology, equipping mobile X-ray vehicles and driving them to the front lines. She opened a training course for female X-ray operators at the Radium Institute, Paris's new center for radioactivity research. Over the course of the war, nearly one million soldiers were examined by X-ray.

After the war, Marie established the Emanation Service, which extracted therapeutic radon gas from her radium to treat cancer patients. In 1920, American journalist Marie Mattingly "Missy" Meloney pledged to raise $100,000 to buy Marie a second gram of radium. Marie sailed to America in May 1921 and received the radium from President Warren Harding at the White House. She was elected to the Académie de Médecine, France's Academy of Medicine, in 1922, the first woman in its ranks. Cataract surgeries in 1923 left her with persistent double vision, forcing her to place colored marks on instrument dials.

In 1924, Frédéric Joliot, a young physics student recommended by Langevin, joined the lab. Marie first assigned him to assist a retiring laboratory preparer; he later worked increasingly under Irène's guidance, and the two married in October 1926. That period brought alarming news: Former lab workers died of radiation-related illnesses, and young women painting luminous watch dials with radium-laced pigment in the United States experienced devastating health effects from ingesting the element.

Through the early 1930s, Marie traveled widely, attending Solvay Councils, elite international physics conferences held in Brussels, while the lab grew to more than 50 researchers. Ellen Gleditsch won appointment as full professor in Norway. In 1932, Irène and Frédéric narrowly missed two major discoveries. They detected a super-penetrating neutral radiation from bombarded elements but misidentified it; James Chadwick at Cambridge correctly identified the emission as neutrons, neutral nuclear particles. Months later, physicist Carl Anderson discovered the positron, an anti-electron that Irène and Frédéric had photographed but failed to recognize.

Their breakthrough came in January 1934. They discovered that alpha-bombarded aluminum created an unstable, previously unknown radioactive isotope of phosphorus before decaying to silicon. By bombarding other elements, they produced additional artificial radioisotopes, demonstrating that nearly any element could be endowed with radioactivity. Frédéric later recalled watching Marie hold the small tube to a Geiger counter, an instrument that detects radioactivity, with fingers "burnt and scarred by radium," calling the moment "without doubt the last great satisfaction of her life."

Marie developed a persistent fever in May 1934 and died at dawn on July 4 at a sanitarium in the Haute-Savoie. The cause was aplastic pernicious anemia, a condition in which bone marrow fails to produce sufficient blood cells, likely caused by decades of radiation exposure. She was buried beside Pierre; her brother Józef and sister Bronya each dropped a handful of Polish soil into the grave.

Irène and Frédéric won the 1935 Nobel Prize in Chemistry for their synthesis of new radioactive elements. Irène directed the Laboratoire Curie, the Curie laboratory in Paris, from 1946 until her death from radiation-induced leukemia in 1956. Ève published the bestselling biography Madame Curie in 1938 and died in 2007 at age 102. In 1995, Marie and Pierre's remains were transferred to the Panthéon, France's national mausoleum for honored figures, making Marie the first woman accorded that honor. In an epilogue, Sobel recounts how Marguerite Perey, Marie's former personal assistant, discovered the element francium in 1939, filling position 87 on the periodic table, and in 1962 became the first woman admitted to the Académie des Sciences. Radium was eventually reclassified as toxic waste, while traditional radium therapy gave way to artificial radionuclides, radioactive isotopes produced in a laboratory, made possible by Irène and Frédéric's work.