ANTOINE CESAR

See also:

• BECQUEREL

BECQUEREL (1788-1878)  , was born at Chatillon sur Loing on the 8th of March 1788 . After passing through the h cole Polytechnique he became ingenieur-officier in 18o8, and saw active service with the imperial troops in Spain from 1810 to 1812, and again in France in 1814 . He then resigned from the army and devoted the rest of his life to scientific investigation . His earliest work was mineralogical in character, but he soon turned his attention to the study of electricity and especially of electrochemistry . In 1837 he received the Copley medal from the Royal Society " for his various memoirs on electricity, and particularly for those on the production of metallic sulphurets and sulphur by the long-continued action of electricity of very low tension," which it was hoped would lead to increased know-ledge of the " recomposition of crystallized bodies, and the processes which may have been employed by nature in the production of such bodies in the mineral kingdom." In biological chemistry he worked at the problems of animal heat and at the phenomena accompanying the growth of plants, and he also devoted much time to meteorological questions and observations . He was a prolific writer, his books including Traite d'electricite et du magnetisme (1834-1840), Traite de physique dans ses rapports aver la chimie (1842), Elements de l'electro-chimie (1843), Traite complet du magnetisme (1845), Elements de physique terrestre et de meteorologie (1847), and Des climats et de l'influence qu'exercent les sots boises et Moises (1853) . He died on the 18th of January 1878 in Paris, where from 1837 he had been professor of physics at the Musee d'Histoire Naturelle . His son, ALEXANDRE EDMOND BECQUEREL (1820-1891), Was born in Paris on the 24th of March 182o, and was in turn his pupil, assistant and successor at the Musec d'Histoire Naturelle; . he was also appointed professor at the short-lived Agronomic Institute at Versailles in 1849, and in 1853 received the chair of physics at the Conservatoire des Arts et Metiers . 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 . It was in connexion with these latter inquiries that he devised his phosphoroscope, an apparatus which enabled the interval between exposure to the source of light and observation of the resulting effects to be varied at will and accurately measured . He published in 1867–1868 a treatise in two volumes on La Lumiere, ses causes et ses effets . He also investigated the diamagnetic and paramagnetic properties of substances; and was keenly interested in the phenomena of electrochemical decomposition, accumulating much evidence in favour of Faraday's law and proposing a modified statement of it which was intended to cover certain apparent exceptions .

He died in Paris on the 11th of May 1891 .