For humanitarian and economic reasons the problem of peptic ulcer1has been and is a great challenge to medical science. The problem of peptic ulcer challenges medical science today because, among the chronic diseases, it ranks tenth as a cause of death and twelfth as a cause of days lost from work.14Among a group of employees of the Metropolitan Life Insurance Co., consisting of approximately an equal number of men (2,125) and women (2,155) above the age of 30 years, the incidence of proved cases was 2.4 per cent during a period of 10 years.15If this incidence prevails in the nation's population, there are approximately 1.5 million people in the United States above the age of 30 in whom peptic ulcers develop during a period of 10 years. It has been estimated from evidence obtained at necropsy that from 5 to 12 per cent of