by James H. Sequeira, M.D. Lond., F.R.C.P. Lond., F.R.C.S. Eng., Physician to the Skin Department and Lecturer on Dermatology at the London Hospital, in charge of Queen Alexandra's Department for Light Treatment, Consulting Dermatologist to the Radium Institute, Secretary at the British Section of the International Association of Dermatology and Syphilology, Fellow (late Secretary of Dermatological Section) of the Royal Society of Medicine, Editor of the British Journal of Dermatology, formerly Physician to the North Eastern (now Queen's) Hospital for Children.