ANDREAS

SIGISMUND

See also:

• ANDREAS SIGISMUND MARGGRAF (1709-1782)

MARGGRAF (1709-1782)  , German chemist, was born at Berlin on the 3rd of March 1709 . After studying chemistry at Berlin and Strassburg, medicine at Halle, and mineralogy and metallurgy at Freiberg, he returned to his native city in 1735 as assistant to his father, Henning Christian Marggraf, chief apothecary at the court . Three years later he was elected to the Berlin Academy of Sciences, which in 1754 put him in charge of its chemical laboratory and in 176o appointed him director of its physics class . He died in Berlin on the 7th of August 1782 . His name is especially associated with the discovery of sugar in beetroot . In 1747 he published an account of experiments undertaken with the definite view of obtaining true sugar from indigenous plants, and found that for -this purpose the first place is taken by beetroot and carrot, that in those plants sugar like that of cane exists ready formed, and that it may be extracted by boiling the dried roots in alcohol, from which it is deposited on cooling . This investigation is also memorable because he detected the nninute sugar-crystals in the roots by the help of the microscope, which was thus introduced as an adjunct to chemical inquiry . In another research dealing with the nature of alum he showed that one of the constituents of that substance, alumina, is contained in common clay, and further that the salt cannot be prepared by the action of sulphuric acid on alumina alone, the addition of an alkali being necessary .