and made an effort to come out of the abdomen; but I prevented it with my hand. The nauseas returned in a few minutes, and I was not a little surprized to see the stomach filled with air, as they came on. In a very little time the organ had become three times its former size; vomiting soon followed this dilatation, and it was evident to all who were present, that the stomach had been compressed without having experienced the least contraction in its fibres. This organ rid itself of air and of a portion of aliments; but, immediately after the exit of these substances, it was flaccid, and it was not till after some minutes, that gradually contracting, it became nearly of the same dimensions as it was before the vomiting. A third vomiting took place, and we saw again the same series of phenomena. For the purpose of ascertaining whence the air came, which, during the nauseas, distended the stomach, I applied a ligature on the stomach near the pylorus, so as to close the communication which exists between this organ and the small intestines, and I made the dog swallow six grains more of emetic in powder. At the end of half an hour the vomiting returned, accompanied by the same phenomena. The distension of the stomach by air was at least as marked as in the preceding experiment; besides there was no appearance of contraction of the stomach, and we could not even clearly distinguish its peristaltic motion. The animal having been killed some moments after, in an experiment which had no relation to vomiting, we examined the abdomen. We saw that the stomach was of considerable size; its texture was flaccid and not all contracted; the ligature, at the pylorus, was not displaced, and the air had not been able to pass this way. Having repeated this experiment and uniformly obtained the same results, I thought it right to conclude with Chirac and Duverney, that the mechanical pressure, exerted on the stomach by the diaphragm and the abdominal muscles, is much concerned in the production of vomiting; now, if it were so, by removing this pressure from the stomach, vomiting would be prevented; experiment confirmed this conjecture.