BECQUEREL'S NOBEL LECTURE

BECQUEREL, HENRI.

Sur Une Propriété Nouvelle De La Matière, La Radio-Active. Les Prix Nobel En 1903.

Stockholm: P.-A. Norstedt & Fils, 1905. Large 8vo. (246x166mm). Original printed wrappers.

First edition of Becquerel's Nobel Lecture.

"Becquerel attended a session of the 'Académie des Sciences' in Paris on 20 January 1896, when Jules Henri Poincaré exhibited a series of radiographs sent to him by Röntgen. He, like others, observed that the emission of X-rays from the cathode tube was accompanied by strong phosphorescence of the glass. He therefore suspected that other forms of induced phosphorescence might be accompanied by other hithero unknown rays.
In February 1896 Charles Henry reported to the 'Académie' his discovery of that phosphorescence could be induced in certain substances by exposure to sunlight. In the same month Becquerel reported that uranium was among these substances. Like all his other early papers on the subject, this appeared in the 'Comptes rendus' and was entitled 'Sur les Radiations Invisibles' émises par les Corps Phosphorescents'. In a second paper, 'Sur quelques Propriétés Nouvelles des Radiations Invisibles', he reported the astonishing fact that uranium was capable of fogging photographic plates even without previous exposure to sunlight and when the plates themselves were completely protected from ordinary light. In a third paper, March 1896, 'Sur les Radiations invisbles émises par les d'Uranium' Becquerel discarded phosphorescence completely and declared that the emanations from uranium constituded an entirely new and unsuspected property of matter, which in his seventh paper he named 'radioactivité'. He also found that the uranium rays discharged a gold-leaf electroscope, which is still used as one method of detecting radio-activity.
Becquerel also discovered that the residue of pitchblende, a natural uranium oxide, after the uranium had been extracted from it was about four times as radio-active as uranium itself. He therefore suggested to the Curies the importance of further investigations of the ore, with the result that they discovered radium. He continued to work on the subject until 1903, in which year he collaborated with Pierre Curie in a paper, 'Action Physiologique des Rayons du Radium', which is the starting-point of the treatment of disease by radio-active substances. In that year he also published ... ('Recherches sur une Propriété Nouvelle de la Matière' - the offered item) ... which is his definitive work, containing a chronological narrative of his investigations, his mature conclusions and a bibliography of two hundred and fourteen treatises on radio-activity, dating from his own first paper in 1896.
The rays emitted by uranium were named in his honour 'Becquerel' rays. They were later discovered to be a composite of three forms of emanation, distinguished by Rutherford (in 1919) as alpha, beta and gamma rays and identified thus: alpha as helium nuclei, beta as electrons, and gamma as powerful X-rays." - (PMM).

In 1903 Becquerel shared the Nobel Prize in Physics with the Curies "in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity".

Order-nr.: 38047