Marie Curie, a French physicist famous for her research on radioactivity, was born on this day in 1867. Madame Curie and her husband Pierre found that a mineral called pitchblende was far more radioactive than its uranium and thorium could account for; that led to their discovery of two more radioactive elements--polonium and radium--in 1898. They received the 1903 Nobel Prize in physics for this work.
After Pierre was killed in 1906, run over by a horse-drawn wagon, Marie took his position at the Sorbonne and became the first woman to teach there. In 1910 she isolated pure radium metal--which earned her a share of another Nobel Prize a year later. During World War I, she helped equip ambulances with x-ray machines and trained doctors on using the new technique. Marie Curie died of cancer in 1934.
[Source: Roy Porter, Ed., The Biographical Dictionary of Scientists (Oxford University Press, ed. 2, 1994).]