Volume 1

The works of John Hunter / edited by James F. Palmer.

Date:
1835-37
Catalogue details

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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    first of these is where only a gradual wasting is produced, either of the whole machine, as in atrophy, or of a part, as in the muscles of a leg or arm, from an injury done to a nerve, tendinous part, or joint: this I call interstitial absorption, because it is the removing a part of the body out of that part which remains, leaving the part still a whole or com- plete part; a muscle, for instance, that is wasted remains still a perfect muscle. The second is where the absorbents are removing whole parts of the body, and this may be divided into natural and diseased. In the natural, these vessels are to be considered as the modellers of the ori- ginal construction of the body; and if we were to consider them fully in this view, we should find that no alteration can take place in the ori- ginal formation of many parts, either in natural growths or in parts arising from disease, without the absorbents being in action to take a considerable part in it. This kind of absorption I shall call modelling absorption. If I was to'consider this function in these lights, it would lead me to a vast variety of facts, as extensive as those connected with any principle in the animal oeconomy, for bones cannot be formed with- out it, nor probably many other parts. A part which was of use in one stage of life, and becomes entirely useless in another, is removed. This is evident in many animals : the thymus gland is removed, the ductus arteriosus and membrana pupil- laris are removed. This process is perhaps more remarkable in the changes of insects than in any other animals. The changes in an insect are very curious. The insect is first a maggot or caterpillar, then goes into the chrysalis state, and comes out a butterfly. Whilst in the chry- salis state it is totally changed, the old parts are almost wholly taken up, and new parts formed; and it is this modelling process that occa- sions these changes*. .Bones do not grow by having new particles put into the interstices of previously formed parts, so as to remove these to a greater distance from each other, by which means they should grow larger,—as, for in- stance, if I put a sponge into water, the water getting into all the interstices makes it larger,—but they grow by the addition of new bone on the external surfacef. * [It must be remembered, however, that in insects, where these changes, as Hunter observes, are the most striking, no proper absorbent vessels exist, and indeed the vas- cular system generally is very imperfect. The changes that take place in the insect transformation have been since ascertained to be rather a development of parts previ- ously existing in a rudimentary state than a total change of parts. In the caterpillar are to be found the rudiments of the future butterfly.] t [See Vol. IV. for a paper detailing the whole of Mr. Hunter’s experiments on this subject.]