V O L . 6 , D O C . 2 8 a O N E M I L WA R B U R G 2 5 AD. [2 157]. Warburg (1846–1931) was a member of the Prussian Academy of Sciences and past president of the Physikalisch-Technische Reichsanstalt. This address was probably delivered impromptu on 30 March 1917 during the celebrations in honor of Warburg’s fiftieth doctoral degree anniversary at the Technische Hochschule in Berlin. At the ceremony, Warburg was presented with an honorary doctoral engineering degree. Several organi- zations jointly presented him with a marble bust by Fritz Klimsch, among them the Deutsche Physi- kalische Gesellschaft, whose chairman at the time was Einstein (see Zeitschrift der Deutschen Gesellschaft für Mechanik und Optik, 1917, p. 72, and Berliner Tageblatt, 31 March 1917, EE, p. 3). Dated by the date of the ceremony. Presumably Karl Strecker (1858–1934), director of the Kaiserliches Telgraphen-Versuchsamt. In his address, he prized “die persönlichen und amtlichen Verdienste des Präsidenten um die innige Verbindung von Physik und Technik” (“the personal and official achievements of the president in regard to the intimate connection of physics and technology” see Stahl und Eisen, 19 April 1917, p. 385). In 1916, Warburg had been made the only honorary member of the Deutsche Physikalische Gesellschaft on the occasion of his seventieth birthday (see Verhandlungen 1916, p. 237).