Otto Warburg signed postcard dated 9^th March 1938. He writes (in German) ‘Dear Professor Reinhard Dohrn. The octopus blood has arrived today in perfect condition. Thank you very much.’

Warburg was a world leading biochemist & German winner of the 1931 Nobel Prize for Physiology. He also served as an officer in the elite Uhlan cavalry during the First World War, being awarded the Iron Cross 1^st Class.