Nuclear Constitution of Atoms. (Bakerian Lecture).

London, The Royal Society, 1920. Royal8vo. Contemp. full cloth. Gilt lettering to spine. A small faint stamp on verso of titlepage and a few other leaves (in lower margins).In: "Proceeding of the Royal Society of London", Series A, Vol. 97. XVIII,470,XXI pp., textillustr. a. 2 plates. Rutherford's paper: pp. 374-400. Clean and fine. First apperance of this famous lecture in which Rutherford predicted the existence of a new constituent of the atomic nucleus and its likely properties. In the lecture Rutherford suggested that "it may be possible for an electron to combine much more closely with the H-nucleus (than is the case in the ordinary hydrogen atom). It is the ontentionof the writer to test (this idea). The existence of such atoms seems almost necessary to explain the building up of heavy elements."Rutherford's collegue Chadwick made several attempts to detect the neutral particle but none was successful until he learned of experiments by the Joliot-Curies in Paris, in which, they said, extremely penetrating gamma rays were emitted. As he suspected, Chadwick found the rays were not gammas but neutrons: and not long afterward Norman Feather, also at the Cavendish, showed that neutrons were capable of causing nuclear disintegrations. Chadwick gave proof of its existence in 1932.…