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,