THE EXISTENCE of an electrical potential difference across the gastric wall has been known for over a hundred years. Crane and co-workers1 refer to the work of Donné in 1834 as probably the earliest measurement of this potential difference. In 1865 Rosenthal2 while investigating the potential difference across the skin of a frog also measured it across the mucosae of the stomach and intestines. Since then numerous attempts have been made to measure and evaluate clinically the gastric potential differences, but the work has progressed slowly because of technical difficulties and the complex nature of the gastric function.
Investigation has proceeded along two basic lines, some investigators attempting to measure only the steady D. C. component, while others have measured only the small superimposed A. C. components. A few investigators have followed a middle course, trying to show the over-all pattern, but owing to the limitations of the