Marie CURIE (1867-1934). L.A.S., Paris May 19, 1904, [to Friedrich Doby?]; 1page in-8 headed Ville de Paris. École municipale de Physique et de Chimie industrielles. General physics. On radium and radioactivity. "As regards radium production, all the information can be found in my book Recherches sur les substances radioactives, published by Gauthier-Villars in Paris. I believe it is this book that you have read in German translation, and I have nothing to add to the description of radium production contained therein"... The letter is mounted at the head of Marie Curie's book, Untersuchungen über die Radioaktiven Substanzen, trans. W. Kaufmann (Braunschweig, F. Vieweg, 1904), signed "Friedrich Doby am 3. Mai 1904" on the title (worn binding).