He was a German chemist who held professorships at Kassel,
Marburg, and Heidelberg.
His early researches on arsenic-containing
compounds cost him an eye in an explosion. He then
turned to gas analysis and spectroscopy, enabling
him and kirchhoff to discover the elements caesium
(1860) and rubidium (1861). He also popularized the
use of the Bunsen burner and developed the Bunsen