Contemporary advances in physics, XXVII the nucleus, second part

In this Second Part the major subject is Transmutation: that is to say, the alteration or disintegration of a nucleus, the unique and distinctive part of any atom, by impacts of fast-moving corpuscles. For the last year and a half the pace of progress in this field has been increasingly rapid, and in all likelihood is destined to become yet swifter. This is partly because of the discovery — a discovery due largely to theoretical foresight — that transmutation of some elements is practicable with protons of a relatively modest energy which can be produced in laboratories without any serious difficulty. Partly it is due to the discovery of neutrons and of deutons, particles which apparently possess remarkable ability in effecting certain kinds of transmutation. Partly also it is due to advances and refinements in the methods of working with alpha-particles, the first variety of corpuscle with which disintegration of nuclei was ever achieved. People are already beginning to speak of “nuclear chemistry” as a special branch of science, and this is already almost justified by the number of cases known in which two nuclei interact and produce two others which are recognizable.