I am fully aware of the honour and responsibility conferred on anyone who is asked to deliver a Maudsley Lecture. That great physician realized that the knowledge of medicine advances by devious paths. I have availed myself of his broadmindedness to lay before you to-day some of the physical symptoms associated with a group of mental cases labelled “acute confusional insanity I will lay before you facts which support the belief that in all these cases the departure from health affects the functions of the whole body, the heat-regulating centre, the cellular and serum defences, the renal functions, the carbohydrate metabolism, and the effect of the injection of insulin on low blood sugar.