Pure gastric juice, as it is secreted by the fundus of the stomach, is an exceedingly corrosive liquid and has the capacity to digest away the normal mucous membrane of the stomach, duodenum, or small intestines and produce a defect indistinguishable from the chronic progressive peptic ulcers seen in patients.1 The mucous membrane is exposed to such pure gastric juice, either when gastric secretion is stimulated by agencies other than food or when an excessive secretion occurs, so that the buffering capacity of food, gastric mucus, swallowed saliva, and regurgitated secretions is overcome. Under normal conditions the mucosa is protected by these buffering agencies and also by an autoregulatory mechanism in the gastrointestinal tract itself. This mechanism provides for a stimulation of gastric secretion during food taking and a check of further secretion when sufficient gastric juice has been secreted to digest the food and before the gastric content