William Stewart Halsted, Professor of Surgery at Johns Hopkins, examines an x-ray plate. Halsted (1852-1922) was an American surgeon who emphasized strict aseptic technique during surgical procedures, was an early champion of newly discovered anesthetics, introduced the use of rubber gloves in surgery and several new operations, including the radical mastectomy for breast cancer. Halsted was one of the "Big Four" founding professors at Johns Hopkins Hospital.