Edward Frankland

Edward Frankland (1825-1899), British chemist, who determined that the atom of one element can combine only with specific numbers of atoms of another element. This concept was expanded and became known as the valence theory, a cornerstone of modern chemistry. Born in Churchtown, Lancashire, England, Frankland started as an apprentice to a druggist and then became a professor of chemistry at several British institutions. He also discovered zinc methyl, the first known organometallic compound—an organic compound containing a metal. With the British astronomer Sir Joseph Norman Lockyer he identified helium as an element, and gave it its name. Helium had been previously observed as a line in the solar spectrum. Frankland was knighted for his work in 1897.