Cohnheim was the master experimental pathologist of the 19th century. He was a pupil of Virchow and Kölliker; in contradiction of the former, he showed the essential feature of inflammation to be the passage of leucocytes through the capillary walls and their accumulation at the site of the injury – “ohne Gefässe keine Entzündung”. His first article on the subject will be found in Virchows Arch. path. Anat., 1867, 40, 1-79.