Sur les radiations émises par phosphorescence. (+) Sur les radiations invisibles émises par les corps phosphorescents. (+) Sur quelques propriétés nouvelles des radiations invisibles émises par divers corps phosphorescents. (+) Sur les radiation... - [THE DISCOVERY OF RADIO-ACTIVITY]

Paris, Gauthier-Villars, 1896. 4to. Bound in contemporary half cloth with marbled boards. ""Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences"", Tome 122 (Entire volume offered). Two title labels with gilt lettering to spine. Minor wear to extremities, upper title label with a few nicks. Library stamp to title page, otherwise a fine and clean copy. Pp. 420-421" Pp. 501-502 Pp. 559-564 Pp. 689-694 Pp. 762-767" Pp. 1086-1088.

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First appearance of the six landmark papers in which Becquerel documents his discovery of Radio-activity, PROMPTING THE NUCLEAR AGE.Becquerel was an expert in fluorescence and phosphorescence, continuing the work of his father and grandfather. Follwing the discovery of X-rays by Röntgen, Bexquerel investigated fluorescent materials to see if they also emitted X-rays. He exposed a fluorescent uranium salt, pechblende, to light and then placed it on a wrapped photographic plate.He found that a faint image was left on the plate, which he believed was due to the pichblende emitting the light it had absorbed as a more penetrating radiation.. However, by chace, he left a sample that had not been exposed to light on top of a photographic plate in a drawer. he noticed that the photographic plate also had a a faint image of the pechblende. After several chemical tests he concluded that these ""Becquerel rays"" were a property of atoms. He had, by chace, discovered radio-activity and prompted thee beginning of the nuclear age. He shared the Nobel Prize for Physics in 1903 with Marie and Pierre Curie. The ""Becquerel Rays"" were later discovered to be a composite of three forms of emanation, distinguished by Rutherford as alpha, beta and gamma rays.Dibner: 163 (the later Mémoire from 1903) - PMM: 393 (1903- Mémoire) - Garrison & Morton: 2001 (only the first paper). - Magie ""A Source Book in Physics"" p. 610 ff. - Norman:157.