The Curies experimented with the ability of uranium to ionize the air and enable it to conduct electricity. When the Curies learned of these developments, they decided to further characterize these phenomena and to ﬁnd, if possible, other sources of Becquerel rays (6). These new rays were termed Becquerel rays. The radiation from the uranium salts was similar to the X-rays, but was produced spontaneously, whereas the X- rays were produced by electron collision. He found that if uranium salts were placed on a photographic plate, the developed plate would show a black negative image of the uranium salts. Shortly afterward, Becquerel, experimenting with the origin of phosphorescence, made an accidental discovery. Further experimentation revealed that X-rays were produced by the collisions of high-energy electrons with a material (6). Foreshadowing the use of the X-ray as a medical diagnostic tool, Roentgen found that the rays could also pass through ﬂesh.

The ability of X-rays and Becquerel rays to penetrate materials that block visible light and cathode rays was intriguing. He learned that the rays could pass through glass as well as “paper, ebony, rubber, and thin layers of metal” (6). Roentgen, in sending a high-voltage electric current through a cathode ray vacuum tube, found that unknown rays were escaping the tube and causing a nearby piece of paper to glow. However, as a result of her groundbreaking experiments, excessive exposure to radioactivity destroyed her body and hastened her death.Īt the end of the 19th century, the Curies were intrigued by the newly-discovered X-rays and Becquerel rays, which had been characterized by William Roentgen and Henri Becquerel, respectively. Through her work with radium and other radioactive elements, Marie won international fame and recognition. Marie remains the only woman in history to have won two Nobel Prizes (5). In 1911, ﬁve years after Pierre’s death, Marie won the Nobel Prize for Chemistry “in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element” (4). Pierre and Marie Curie won the Nobel Prize for Physics in 1903 “in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel” (3). Radium will always be tied to its discoverer, the remarkable Marie Curie. Though it fell out of favor within 30 years of its discovery, radium was vitally important to the discovery and characterization of radioactivity. Five “Radium Girls” died as a result of their ingestion of the radioactive element and the resulting scandal branded radium a killer (2). The girls would even paint their nails and teeth with the radium paint to make themselves glow in the dark. The dentist learned that the girls would lick their radium-laced paintbrush bristles to make the tips ﬁner. A New Jersey dentist noticed that several of the factory girls who painted watch dials had developed “diseased jawbones that failed to heal after dental work” (1). Famously, radium was used for its luminous properties to make watch dials glow in the dark.

One company advertised it as “liquid sunshine” (2). It was used to treat “almost everything from impotence to insanity” (1). Marketed as a cure-all, radium was an ingredient in a variety of over-the-counter nostrums, from face creams to tonic waters. In the 1920s, many Americans and Europeans were regularly consuming radium.

Radium glow in the dark