(Paris, Gauthier-Villars), 1899. 4to. No wrappers. In: "Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences", Tome 128, No 13. Pp. (753-) 852. (Entire issue offered). Becquerel's paper: pp. 771-777.
First appearance of Henri Becquerel last paper on radio-activity in the first period, two years after his monumental discovery of radioactivity.
Order-nr.: 47426