Comptes Rendus, 1900.
4 pages (73-76) in: Comptes Rendus des Seances de L'Adademie des Sciences Volume 130, No. 2. IN THE SAME ISSUE: SKLODOWSKA-CURIE, Marie. Sur la Penetration des Rayons de Becquerel non Deviables par le Champ Magnetique. 4 pages (76-79). Slim 8vo, modern printed wrappers. Paris: Comptes Rendus des Seances de L'Academie des Sciences, 1900. A very good(+) copy
"Pierre Curie had just demonstrated that there are at least two different kinds of rays, subsequently known as A and B-rays, emitted from radioactive substances, since in a magnetic field one is deviated while the other is not. Marie Curie, in an independent inquiry, found that the former rays have a much smaller penetrating power than the latter; these less penetrative emanations are idential with A-rays."
Condition: Very Good(+)