Department of Chemical Pathology, London Hospital Medical College.

Pathological Laboratory, Royal Berkshire Hospital, Reading.

The Department of Chemical Pathology, Westminster Hospital Medical School, London, S.W. 1, and the National Institute for Medical Research, Hampstead, London, N.W. 3.

Frank Billings Medical Clinic, Department of Medicine, The University of Chicago, Chicago, Ill.

Department of Medicine, the University of Chicago.

Veterans Administration Hospital, Manhattan Beach, Brooklyn, New York.

Department of Internal Medicine, University of Virginia Medical School, University of Virginia Hospital, Charlottesville, Va.

Hospital of the Rockefeller Institute for Medical Research, New York City.

Section of Preventive Medicine, Yale University School of Medicine, New Haven.

Neurological Institute of New York, New York City.