Dr. J. Chadwick, F.R.S.

Abstract

DR. JAMES CHADWICK, fellow of Caius College, Cambridge, and assistant director of research in the Cavendish Laboratory, has been appointed to the Lyon Jones chair of physics in the University of Liverpool as from October 1 next, in succession to Prof. L. R. Wilberforce, who retires at the end of the present session. Dr. Chadwick is one of the most distinguished of the younger physicists in Great Britain. His early work on a-, p- and y-radiation led to the experimental proof of Moseley's deduction that the charge on the nucleus was equal to the atomic number. Then, in association with Lord Rutherford, he carried out investigations on the anomalous scattering of a-particles by light elements, which gave information on the size and structure of the nucleus of the atom, while another line of work demonstrated the artificial transmutation of certain lighter elements by a-particle bombardment. Improvements in the technique of counting such particles led to the discovery of definite nuclear a-particle and proton levels. The obscure effects observed by M. and Mme. Curie-Joliot when beryllium was bombarded with oc-particles were investigated by Dr. Chadwick, and immediately he recognised that they could be explained by assuming the ejection of a particle having mass but no charge. This assumption he quickly proved in a brilliant series of experiments, and a new elementary particle, the neutron, which has proved of wide importance in investigations on atomic structure, was made available to the physicist. The value and originality of Dr. Chad-wick's work has been recognised by his election to a fellowship of the Royal Society, by the award of the Hughes Medal of the Society in 1932 and other distinctions.