Karl Gottfried Hagen
Karl Gottfried Hagen (24 December 1749 – 2 March 1829) was a German chemist. Hagen was born and died in Königsberg, Prussia. He founded the first German chemical laboratory at the University of Königsberg, thus establishing the scientific discipline of pharmaceutical chemistry in Germany. He worked as a Professor in the field of physics, chemistry and mineralogy. His daughter, Johanna, married the astronomer Friedrich Wilhelm Bessel. Another daughter, Louise Florentine, married the physicist Franz Ernst Neumann.