Rudolf Ludwig Karl Virchow ( 13 October 1821 â `` 5 September 1902 ) was a German doctor , anthropologist , pathologist , prehistorian , biologist and politician , known for his advancement of public health . Rudolf Ludwig Karl Virchow ( 13 October 1821 -- 5 September 1902 ) was a German doctor , anthropologist , pathologist , prehistorian , biologist and politician , known for his advancement of public health .