IN a nursing home at Exeter, William Dobinson Halliburton passed away, peacefully, on the evening of May 21. With his death the physiological world loses one of its most outstanding personalities, King's College one of its most loyal friends, and those who knew him, one who occupied, in their affection, a place it will not be possible to fill. For Halliburton was unique. To many is given knowledge, to many also the power to impart it. A few have the intuitive faculty of investigating the fundamentals of their subject and of guiding the steps of others in the uncharted pathways of original research. How restricted is the number who combine these attributes with patience apparently unlimited, calmness in times of stress, encouragement when disappointments came, and never, by word or deed, acted other than in the spirit of reasonableness. Yet such was Halliburton.