Licence: Public Domain Mark
Credit: The works of John Hunter / edited by James F. Palmer. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![when the teeth drop out of themselves, or lire taken out by art; as also the fangs of the shedding teeth, which allow them to drop out; and it is by this means also that ulcers are formed. It becomes in many cases a substitute for mortification, in which cases it seems to depend upon a degree of strength and vigour superior to that where mortification hap- pens ; and in many cases it finishes what mortification had begun, by separating the dead part. From all this, we must see that the causes of the absorption of whole parts are many. Pressure appears to be one of the greatest causes of absorption, and it is commonly a cause of the progression. It produces its effects not in all cases in proportion to the pressure, but according to the pressure and other circumstances combined; for we find very different effects from the same quantity of pressure : thus, under one circumstance, pressure shall give signs of strength, and produce an increase, or thickening; but under another circumstance the same quantity of pressure shall produce waste, or an absorp- tion of the parts. This difference in effect, from the same quantity of pressure, depends upon the pressure being from without or within, for the first effect of the irritation of pressure from without is the disposition to thicken, which I have asserted is rather an operation of strength; but if it exceeds the irritation of thickening, then the power ap- pears to give way to it, and the absorption of the parts pressed gives way to it. Pressure produced by an extraneous body surrounded on all sides, such as pus in an abscess, acts equally on every side of the surrounding parts, and therefore, every part being pressed alike, ought, from this cause singly considered, to produce absorption of those surrounding parts equally on all sides, supposing the parts themselves similar in structure, or, which is the same, equally susceptible of being absorbed : but we find that one side only of the surrounding living parts is susceptible of this irritation; therefore one side only is absorbed, and this goes on in regular progression. The side of the cavity which is susceptible of this irritation is always that which is next to the ex- ternal surface of the body; therefore we have always extraneous substances of every kind determined to the skin, and to that side of the body on which the extraneous sub- stance lies, or to which it is nearest, and that without having any effect upon, or pro- ducing the least destruction of, any of the surrounding parts. From this cause we find abscesses whose seat is in or near the centre of a part readily determined to the surface or side in preference to another; and whenever the lead is once taken, absorption goes on there only. But as some parts of the body are more susceptible of this irritation than others, we find that such parts are often absorbed, although they are not in the shortest road to the skin; and of such structure is the cellular membrane. We find exfoliations of bones, as well as all other extraneous bodies, approaching the skin in like manner, and from the same cause. But the progressive absorption is always more or less attended with the interstitial, and assisted by it. The vessels in general would appear to have more powers of perfecting themselves when injured than any other part of the body, for their use is almost immediate and con- stant, and it is they which perform the operation of restoration on the other parts; therefore they themselves must first be perfect. They would seem to have more of the polypus in them than any other part of the body. This is perhaps more in the absorb- ents than in the arteries and veins, for we can conceive a part injured by accident, and, as it were, standing still for a little while ; but we see ulceration going on very rapidly, which proves an immediate formation of vessels for absorption*.] * The preceding paragraphs are transcribed from the Hunterian Catalogue (Phys. Series, vol. ii. p. 5), and are also partly repeated in the work on Inflammation. They are in Mr. Hunter’s own words, and serve to complete this subject. A long and interesting note is added to this part of the Catalogue by the author,](https://iiif.wellcomecollection.org/image/b21996623_0001_0286.jp2/full/800%2C/0/default.jpg)
