MECHANISM OF VOMITING.
To the Editor of the London Medical Gazette.
Glasgow University, Nov. 26, 1828.
Sir,
Having lately perused, in the 35th Number of the Medical Gazette, some observations "on the mechanism of the act of vomiting," by Dr. Marshall Hall, in which, after controverting the different opinions which have been entertained by physiologists on this question, he endeavours to prove that vomiting is an effort, not of inspiration, but of expiration, and advances this opinion as having originated in himself, I beg, through the medium of your Journal, to refer that gentleman to Richerand's Physiology, where, on the subject of vomiting, page 70, he says, "Sometimes the action of the muscular fibres of the stomach is quite inverted; they contract from the pylorus towards the cardia; and this antiperistaltic motion, in which the contractions act with more force and rapidity, and in a manner decidedly convulsive, produces vomiting. The action of the abdominal muscles then connects itself with that of the stomach; the viscera are propelled upwards and backwards, by the contraction of the large muscles of the abdomen; the diaphragm ascends towards the chest; if it descended, in contracting, the œsophagus that passes between its two crura would be compressed, and the expulsion of food through the cardia could not be effected. It is also observed, that during expiration only, any thing can pass from the stomach into the œsophagus." Again, on respiration, page 147—"In every effort of expiration, as coughing and vomiting," &c. Here, then, we see that Dr. Hall's views, as far as regards vomiting being an effort of expiration, have long since been advanced by Richerand.
The profession are certainly much indebted to Dr. Hall for his corroboration of these views; at the same time he should not have taken to himself the merit of having first suggested them.
Sir,
Your most obedient servant,
A Subscriber.