Becquerel, Alexandre Edmond

Born Mar. 24, 1820, in Paris; died there May 11, 1891. French physicist. Member of the Académie des Sciences. Son of Antoine César.

Becquerel’s works were devoted to the phenomena of phosphorescence. Becquerel demonstrated that the spectrum of phosphorescence is independent of the spectrum of exciting radiation; he established the decay law for phosphorescence and demonstrated that the intensity of phosphorescence is dependent on temperature. He also built a phosphoroscope—an instrument for observing luminescence of short duration—and devised a system of classification for phenomena of phosphorescence. His research contributed greatly to research on luminescence. Becquerel also studied atmospheric electricity, infrared spectra, and photography.