August Beer

August Beer (1825 to 1863) was a German physicist, chemist and mathematician of Jewish descent, born in Trier. He studied mathematics and the natural sciences there and, from 1845, at Bonn under the mathematician and physicist Julius Plucker, whose assistant he later became. In 1848 he won a prize for an essay on the position of the optic axes in biaxial crystals and obtained his doctorate, and two years later he became a lecturer at the University of Bonn. His 1852 paper on the absorption of red light in coloured aqueous solutions of salts showed that the intensity of light transmitted through a solution falls exponentially with the path length and the concentration of the solute, which together with the earlier work of Johann Heinrich Lambert makes up the Beer-Lambert law. He also devised a photometer, wrote an Einleitung in die hohere Optik in 1854 and was appointed professor of mathematics at Bonn in 1855.