The application of neutral red as a vital stain has been a wide one since its introduction by Ehrlich into medicine. Its use in the study of gastric secretory functions dates from Fuld's1work on dogs with Pawlow pouches in 1908, in which he demonstrated its excretion into the pouch, when the dye was instilled into the main stomach. Finkelstein,2in 1922, injecting neutral red and other dyes subcutaneously, studied the excretion into Pawlow pouches and substantiated Fuld's earlier observations. Glaessner and Wittgenstein,3in 1923, applied this knowledge to the formulation of a "gastric function test," using as their criterion the appearance time of the dye in the stomach after intra-muscular injection. Subsequently, publications by Simici and Dumitriu,4Koopman,5and Carnot and Gaehlinger6have emphasized the usefulness of this procedure. The studies reported here aim particularly to consider the clinical usefulness of determining the