Page:Popular Science Monthly Volume 81.djvu/309

Rh explained the prompt vanishing of the ache soon after we begin to eat, for repeated swallowing results in continued inhibition. Furthermore, Ducceschi's discovery that hydrochloric acid diminishes the tonus of the pyloric portion of the stomach -may have its application here; the acid would be secreted as food is taken and would then cause relaxation of the very region which is most strongly contracted.

The Concomitance of Contractions and Hunger in Man.—Although the evidence above outlined had led me to the conviction that hunger results from contractions of the alimentary canal, direct proof was still lacking. In order to learn whether such proof might be secured, one of my students, Mr. A. L. Washburn, determined to become accustomed to the presence of a rubber tube in the oesophagus. Almost every day for several weeks Mr. Washburn introduced as far as the stomach a small tube, to the lower end of which was attached a soft-rubber balloon about 8 cm. in diameter. The tube was thus carried about each time for two or three hours. After this preliminary experience the introduction of the tube, and its presence in the gullet and stomach, were not at all disturbing. When a record was to be taken, the balloon, placed just below the cardia, was moderately distended with air, and was connected with a water manometer ending in a cylindrical chamber 3.5 cm. wide. A float recorder resting on the water in the chamber permitted registering any contractions of the fundus of the stomach. On the days of observation Mr. Washburn would abstain from breakfast, or eat sparingly; and without taking any luncheon would appear in the laboratory about two o'clock. The recording apparatus was arranged as above described. In order to avoid the possibility of an artifact, a pneumograph, fastened below the ribs, was made to record the movements of the abdominal wall. Between the records of gastric pressure and abdominal movement, time was marked in minutes, and an electromagnetic signal traced a line which could be altered by pressing a key. All these recording arrangmentsarrangements [sic] were out of Mr. Washburn's sight; he sat with one hand at the key, ready whenever the sensation of hunger was experienced to make the current which moved the signal.

Sometimes the observations were started before any hunger was noted; at other times the sensation, after running a course, gave way to a feeling of fatigue. Under either of these circumstances there were no contractions of the stomach. When Mr. Washburn stated that he was hungry, however, powerful contractions of the stomach were invariably being registered. As in the experience of the psychologists, the sensations were characterized by periodic recurrences with free