Meyer, Viktor (1848-1897)

German organic chemist who invented an apparatus for determining vapour densities (and hence molecular weights), now named after him. He was also the discoverer of the heterocyclic compound thiophene (see organic chemistry. Meyer was born in Berlin and studied there and at Heidelberg and Württemberg. At the age of 22 he was appointed professor at Stuttgart Polytechnic, in 1885 at Göttingen, and in 1889 at Heidelberg. In 1871, Meyer experimentally proved Avogadro's hypothesis by measuring the vapour densities of volatile substances (molecular weight, or relative molecular mass, is twice the vapour density). He went on to determine the vapour densities of inorganic substances at high temperatures. From benzene obtained from petroleum, Meyer in 1883 isolated thiophene, a heterocyclic compound containing sulphur, which much later was to become an important component of various synthetic drugs. Meyer published Textbook of Organic Chemistry 1883-96 and, with his brother Karl, Pyrotechnical Research 1885.