Eminent Polish-French scientist (1867–1934) who won Nobel Prizes in Physics (1903) and Chemistry (1911). Her discovery of the elements of radium and polonium and her subsequent experiments revolutionized the understanding of radioactivity and proved to be one of most far-reaching scientific developments of the twentieth century. Scarce TLS in French signed “M. Curie,” one page, 5.25 x 8.25, Faculté des Sciences de Paris letterhead, September 15, 1927. Curie writes to Professor Kovarik at the Sloane Laboratory at Yale University. In full (translated): “I just received your letter concerning Professor Boltwood, I had absolutely no idea about his sad end. I sincerely thank you for your thoughtfulness in writing me to inform me of the circumstances in which this tragedy occurred. Believe that I feel very deeply the loss of such distinguished scientist and that I realize how much this loss is particularly sensitive to you and Yale University. My daughter joins me in expressing our regrets.” American chemist Bertram Borden Boltwood (1870–1927) discovered that radium is a disintegration product of uranium, providing an important insight into Curie’s original discovery of radium and laying the groundwork for the development of radiometric dating. Accompanied by the original mailing envelope. A touch of very subtle soiling to blank portion, otherwise very fine, bright condition. Auction LOA John Reznikoff/PSA/DNA and R&R COA.