In a former paper1 we recorded two experiments on the acid control of the pylorus in infants. We have since extended and verified these results and present them herewith, together with a partial description of the first experiments.
The explanation of the opening and closing of the pylorus was not fully made until Pawlow and Cannon's work was done. Not long after Beaumont's experiments in 1832 it is true that Hirsch, by means of a duodenal fistula in a dog, came to the conclusion that acid on the duodenal side caused the pylorus to close, but he abandoned his idea in favor of von Mering's observations, made about the same time, that the closure of the pylorus was due to the bulk of liquid or food in the duodenum. In his experiments von Mering introduces milk into the duodenum. The observation that the mechanical effect of inflating