Julius Friedrich Cohnheim

Julius Friedrich Cohnheim (1839 to 1884) was a German-Jewish pathologist born at Demmin in Pomerania. After studying at several German universities and taking his doctorate at Berlin in 1861, he worked under Rudolf Virchow, then held chairs in pathological anatomy and general pathology at Kiel, Breslau and finally Leipzig, where he remained until his early death. He is remembered for showing in 1867 that the white blood cells leaving the vessels in inflamed tissue are the source of pus, a result that reshaped the theory of inflammation. He was also an early user of freezing to prepare fresh tissue for microscopic study, studied circulation and the causes of embolism, and was admired as a teacher whose students carried his experimental approach into later pathology.