Been made use of by Becquerel in his investigations of infra-red radiations.
Edmond Becquerel was associated with his father in much of his work, but he himself paid special attention to the study of light, investigating the photochemical effects and spectroscopic characters of solar radiation and the electric light, and the phenomena of phosphorescence, particularly as displayed by the sulphides and by compounds of uranium.
After the discovery of the radioactive properties of uranium by Henri Becquerel in 1896, it was noticed that some minerals of uranium, such as pitchblende, were more active than the element itself, and this circumstance suggested that such minerals contained small quantities of some unknown substance or substances possessing radioactive properties in a very high degree.
Like the X rays, the Becquerel rays are invisible; they both traverse thin sheets of glass or metal, and cannot be refracted; moreover, they both ionize gases, i.e.
Antoine Henri Becquerel (1852-1908), son of the lastnamed, who succeeded to his chair at the Musee d'Histoire Naturelle in 1892, was born in Paris on the 15th of December 1852, studied at the Ecole Polytechnique, where he was appointed a professor in 1895, and in 1875 entered the department des posts et chaussees, of which in 1894 he became chef.
The Becquerel rays have a marked chemical action on certain substances.
Antoine Cesar Becquerel (1788-1878), was born at Chatillon sur Loing on the 8th of March 1788.
C. Becquerel (1788-1878), G.