Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ... ; with notes by Richard Owen.
- John Hunter
- Date:
- 1840
Licence: Public Domain Mark
Credit: Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ... ; with notes by Richard Owen. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
87/484
![hardly to be observable, and that it cannot be felt by the hand. i/S ltSu°aVlty is vevy sma11' and must be capable of adapting itself to the quantity it contains (or it could not possibly grind), much motion is not necessary for the purposes of trituration: a swelling and collapsing, like the motion of the heart, would have no effect. The extent of motion in grindstones need not to be the tenth of an inch, if their motion is alternate and in contrary di- rections. But although the motion of the gizzard is hardly visible, yet we may be made very sensible of its action by putting the ear to the sides of a fowl while it is grinding its food, when the stones can be heard moving upon one another.* It may be remarked, that the motion of the whole intestinal canal, from the fauces to the anus, is naturally so slow, as not to be ex- cited into quick actions. The food passes slowly along the oeso- phagus ; and in a man, fluids which might be expected to act even by their own gravity, descend but slowly; yet 1 think we may be certain that the oesophagus has always *a regular contraction, and that the lower parts must relax in progression as it contracts above; so that no position of the body makes any difference in this action. Upon exposing the stomach in living animals it does not appear much agitated or affected, even by being handled or otherwise irritated. The same thing may be observed in the whole track of intestines: and we find that when the fasces are expelled by the action of the gut alone, that the explusion is slow; the stomach and rectum, however, can be emptied at once; but that is done by the abdominal and other muscles. We know that the action of vomiting is performed entirely by the diaphragm and abdominal muscles ; and we know that by the same action the contents of the rectum can be expelled. Neither is any other power required to empty the stomach in vomiting, these muscles being often capable of forcing the bowels themselves out of the abdomen, and of pro- ducing a rupture. It is not necessary the stomach itself should act violently to produce an evacuation of its contents; nor is it even necessary it should act at all; for the lungs themselves do not act in the least when any extraneous matter is to be thrown up; and coughing is to the lungs what vomiting is to the stomach.f The * [Harvey makes a similar observation on birds of prey : Falconibus, aquilis, aliisque avibus ex praeda viventibus, si aurem prope admoveris dum ventriculus jejunus est, manifestos intus strepitus, lapillorum illuc ingestorum, invicemque collisorum percipias.— Opera Omnia, 4to., p. 208. These investigations by means of the ear relative to the internal actions of animal bodies deserve a place in the history of auscultation.] •f- [The conclusion which Hunter deduces from philosophical and just analogies, with respect to the share performed by the stomach in the act of vomiting,°has not been considered satisfactory, at least if we may judge from the experiments which have subsequently been made with a view to determine that point. But perhaps M. Majendie was not aware of what our illustrious physiologist had written on the subject, as he introduces his experiments to our notice as if the passive state of the stomach in vomiting had never before been suspected : On a cru long-temps que le vomissement dependait de la contraction brusque et con- 12](https://iiif.wellcomecollection.org/image/b21131545_0087.jp2/full/800%2C/0/default.jpg)
