Doctoral thesis: Recherches sur les substances radioactives

In June 1903 Marie Curie defended her thesis at the Sorbonne. The jury was Gabriel Lippmann, her supervisor, with Edmond Bouty and Henri Moissan, who would win the Nobel Prize in Chemistry later that year. Her sister Bronya came from Poland and insisted she buy a new dress; Marie chose a black one she could wear in the laboratory.

The thesis set out everything: the measuring method, radioactivity as an atomic property, the survey of elements and minerals, the radiochemical method, the discovery of polonium and radium, the preparation of radium chloride and its atomic weight, and early studies of the rays. She was awarded the degree with the mention *très honorable*, among the first doctorates in science earned by a woman in France.

Ernest Rutherford joined the celebration dinner that evening. Months later came the Nobel Prize. The thesis went into a second edition in 1904 and was translated into English, German and other languages.