Julius Plücker

Julius Plücker was a German mathematician and physicist, born in Elberfeld in 1801, who studied in Bonn, Heidelberg, Berlin and Paris and became a professor at Bonn. In geometry he made fundamental contributions to analytical geometry, introducing abridged notation and establishing projective duality on an independent footing, and he extended the study of Lamé curves. After moving to the chair of physics he pioneered the study of discharges in vacuum tubes, work on cathode rays that led eventually to the discovery of the electron, and he worked with Johann Hittorf on the spectroscopy of gases.