On December 26, 1898, chemists Marie Curie, her husband Pierre Curie, and colleague Gustave Bémont announced a groundbreaking discovery of two new radioactive elements: radium and polonium. This research, conducted at the Paris Municipal School of Industrial Physics and Chemistry, would pave the way for significant advancements in medicine and science, while tragically impacting the life of one of the researchers.
Marie Curie, then a medical student at the Sorbonne, ventured into the field of radiation for her thesis. In the preceding years, notable discoveries had set the stage for her work. In 1895, Wilhelm Röntgen discovered X-rays, followed by Henri Becquerel‘s accidental finding of weak rays emitted by uranium salts. These developments allowed Curie to bypass extensive prior research and focus on experimental work.
In a cramped storeroom provided by Pierre, Marie began her research using a device called the piezoelectric quartz electrometer, invented by her brother-in-law, Jacques Curie. This device measured the weak electrical currents produced by radioactivity. As she reported in a 1904 article for Century magazine, Curie preferred to measure the conductivity of air exposed to radiation rather than relying solely on photographic plates.
Curie’s experiments led her to study pitchblende, a mineral rich in uranium. She observed that pitchblende exhibited a radioactivity far greater than uranium itself. In her words, “How could an ore, containing many substances which I had proved inactive, be more active than the active substances of which it was formed?” This inquiry drove her to theorize that a previously unknown element must be present in the ore.
Working alongside Pierre and Bémont, the team sought to isolate the radioactive substances from pitchblende. Their efforts bore fruit when they identified polonium, which was approximately 60 times more radioactive than uranium, in July 1898. Shortly thereafter, on December 21, they discovered radium, an astonishing 900 times more radioactive than uranium. The Curies presented their findings at the French Academy of Sciences on December 26.
Over the following years, the Curies successfully isolated both elements, working in a poorly ventilated shed situated across from their original workspace. Their pioneering research on radioactivity earned them the Nobel Prize in Physics in 1903, alongside Becquerel. Initially overlooked in the prize considerations, Marie’s contributions were acknowledged only after Pierre’s insistence on her inclusion.
Marie Curie would later receive a second Nobel Prize in 1911, this time in chemistry, for her extensive work on radium. Following Pierre’s death in 1906, Marie continued her advocacy for the medical application of X-rays. She developed mobile X-ray units for battlefield use during World War I, significantly enhancing medical care for injured soldiers.
Despite her remarkable contributions, the dangers of radiation exposure took a toll on both Marie and Pierre. They experienced frequent radiation sickness and burns from their work. It is widely believed that Marie’s exposure to radiation ultimately led to her death from aplastic anemia, a type of leukemia linked to radiation damage, in 1934 at the age of 66.
Curie’s discovery fundamentally transformed the scientific landscape and laid the groundwork for future advancements in treatment methods, particularly in cancer therapy. The notebook she used during her 1898 discovery remains radioactive and is preserved in a lead box, serving as a poignant reminder of the risks and rewards of scientific inquiry.
