[ Autographs ] MAX PLANCK (1858 - 1947) German physicist and Nobel Prize winner who originated and developed black body radiation and quantum theory. His name is honored in Planck's Contant. A.L.S. "Max u Mayn Planck" on the verso of a postcard, Berlin, Dec. 29, 1923, in German to the von Euler-Chelpins, thanking them for their Christmas present and wishing them a happy New Year. Very good.