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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    system, called the lymphatics, though long known, was not in the least suspected of performing the operation of absorption, but was still sup- posed to be the terminations of the extreme ends of the arteries, not large enough to carry red blood but only serum or lymph, though from their similarity to the lacteals, which were known to be absorbents, it became at last evident to common sense that they must absorb. Before this idea was started, the general opinion of the vascular sy- stem ran thus. The arteries were supposed to carry blood for nourish- ment, secretion, &c. throughout the machine; the veins to return the red blood, as also to absorb from every surface of the body; the lym- phatics to return the lymph or blood which came along the arteries; and the lacteals to absorb part of the chyle from the intestines. But some experiments which I made to ascertain whether the veins of the mesentery absorbed, proved that they had not the power of absorption*. I do not suppose the veins, even in an erection of the penis, to have the power of absorption; but I consider the corpora cavernosa as veins through which the blood is constantly flowing from the arteries, and that other veins carry off the blood from the corpora cavernosa; that in erection there is a spasm on the extremities of these veins, which prevents the blood from flowing into them, in consequence of which an accumulation and distension takes place, which causes an erection, and this ceases with the spasm on the veins. By tying the veins of a dog’s penis, I found I could cause an erection at pleasure, while the arteries continued freef. Now, therefore, the offices of the three systems of vessels were as follow. The arteries remain as before ; the veins reconvey the blood to the heart, for a continuance of the actions of the arteries as before, but have lost their supposed power of absorb- ing ; the absorbents alone are employed to take up whatever is to be carried into the circulating system. Now let us consider what are the substances always allowed to be absorbed. 1st, Extraneous matter, in * TSee the details of these experiments in Vol. IV.] f [In 1830 Mr. Houston announced the discovery of a muscle in the human subject which arises from the ramus of the pubes, and, crossing the dorsum of the pcenis to unite with its fellow in the mesial line, effectually compresses the dorsal vein whenever this muscle is brought into action. (Dub. Hosp. Rep. Vol. V. p. 459.) A similar muscle, but more perfectly developed, was much earlier discovered by Cuvier in several of the mammalia, to which that eminent anatomist assigned the true use (Anat. Comp. Vol. V. p. 102); in addition to which we may mention that the tongue of the chameleon possesses a highly erectile tissue, and is provided with a similar pair of muscles adapted to fulfil the same object. Tiedemann, Cuvier, Moreschi, &c. have confirmed the accuracy of Hunter’s opinion respecting the structure of these tissues, namely, that they consist of veins enlarged at their origins, and not of a system of cells as has generally been supposed.]