Irving Langmuir (1881-1957), American chemist and Nobel laureate, known for his work in many phases of chemistry, theoretical and applied. Langmuir was born in Brooklyn, New York, and educated at Columbia University and the University of Göttingen. In 1932 he became associate director of the research laboratory of the General Electric Company and served in that capacity until his retirement in 1950. He worked on the development of gas-filled tungsten lamps, electron-discharge apparatus, high-vacuum pumps, and the atomic-hydrogen welding torch. Langmuir and the American chemist Gilbert Lewis developed a theory of chemical attraction and valence based on the structure of the atom, known as the Langmuir-Lewis theory. Langmuir's research in cloud physics led to the artificial stimulation of rainfall by cloud seeding. For his work on monomolecular films and surface chemistry he was awarded the 1932 Nobel Prize in chemistry.