Pierre and Marie Curie, French physicists, 1904.

Chromolithograph by Imp of Pierre Curie (1859-1906) and his wife Marie (1867-1934) who were two of the first people to work on radioactivity, discovering radium and polonium. They treated two tonnes of ore to isolate one tenth of a gram of radium. After Pierre Curie was killed in a street accident in Paris in 1906, Marie continued her research, becoming the first woman profesor at the Sorbonne and winning the Nobel Prize twice (1903 and 1911). From 'Vanity Fair' magazine.