SINCE 1948, when Prof C. E. Dent established his unit for the study of human metabolism at University College Hospital, London, it has been his practice to provide space for one or two overseas visitors to work in the unit each year. These visitors are selected from a list of applicants, and over the years it has so happened that the majority have come from the United States. I do not intend to list these people, lest I should inadvertently leave anyone out, but most of their names are now well known in the field of human metabolism.
Mary Efron made no such formal entry to our department. Her former husband, Bob Efron, came to London to work at the National Hospital at Queen's Square and Mary, although she had two children to care for, soon decided that she had time to spare and looked around for something useful to