Andreas Sigismund [1709-1782]

German chemist, a pioneer in analytical chemistry. He proved that alumina, magnesia, and lime are distinct earths, found (1743) an improved method for the commercial preparation of phosphorus , and isolated (1746) zinc . In 1747 he announced his discovery of sugar in the beet. Marggraf directed, from 1754, the chemical laboratory of the Berlin Academy of Sciences.