Certificate isued by the Institute de Radium, December 1926.

Certificate to specify radium content signed by Marie Curie in her role as director of the Institute de Radium. Pierre Curie (1859-1906) and his wife Marie (1867-1934) were two of the first people to work on radioactivity, which was originally discovered by Henri Becquerel (1852-1908). The Curies investigated it further to produce radium and polonium, and won the Nobel Prize for Physics in 1903 for their work on radioactivity. After Pierre Curie was killed in a street accident in Paris, Marie continued her research, becoming the first woman profesor at the Sorbonne. She won the Nobel Prize for a second time in 1911.