Abstract
James Macdonald Cassels was a physicist who, in the course of his career, encompassed a wide range of interests. As a research student he pioneered a new branch of research in the study of solids by slow neutron scattering. While still in his twenties he played an important part in persuading the Government to join the fledgling C.E.R.N. organization in Geneva. By research on the synchrocyclotrons at Harwell and Liverpool he established himself internationally as an authority in the field of high-energy particle physics. Occupying the Liverpool Chair once held by Chadwick he continued the work of his predecessor in developing the Physics Department as a centre of excellence, with the provision of new facilities and the establishment of the nearby Daresbury Laboratory. For many years he was active in the promotion of energy conservation through the concept of combined heat and power from power stations. Towards the end of his career he suffered increasingly from ill-health.