Meyer, (Julius) Lothar (1830-1895)

German chemist who, independently of his Russian contemporary Dmitri Mendeleyev, produced a periodic law describing the properties of the chemical elements.

Meyer was born in Varel, Lower Saxony, and studied at Zürich, Switzerland, and at several German universities. He was professor of chemistry at Karlsruhe Polytechnic 1868-76, and at Tübingen University for the rest of his life.

In his book Die modernen Theorien der Chemie/Modern Chemical Theory 1864, Meyer drew up a table presenting all the elements according to their atomic weights (relative atomic masses), relating the weights to chemical properties. In 1870 he published a graph of atomic volume (atomic weight divided by density) against atomic weight, which demonstrated the periodicity in the variation of the elements' properties. He showed that each element will not combine with the same numbers of hydrogen or chlorine atoms, establishing the concept of valency and grouping elements as univalent, bivalent, trivalent, and so on.

Meyer never claimed priority for his findings and, unlike Mendeleyev, he made no predictions about the composition and properties of any elements still to be discovered.