SCHWEITZER, Albert (1875-1965). Autograph letter signed ("Albert Schweitzer"), to Reverend R.F. Rattray. Lausanne, Switzerland, 23 September 1955. 5 pages, 8vo, bifolium and one half sheet, with original envelope. Responding to an invitation to give the Hibbert Lecture at Cambridge University, and commenting that he only lectures in French or German. He expresses grief over the death of his dear friend Professor Burkitt in Cambridge: "His death deeply grieved me. I owe him so much."