On spontaneous gangrene from arteritis and the causes of coagulation of the blood in diseases of the blood-vessels / by Joseph Lister.

Date:
[1858?]
Catalogue details

Licence: Public Domain Mark

Credit: On spontaneous gangrene from arteritis and the causes of coagulation of the blood in diseases of the blood-vessels / by Joseph Lister. 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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    favour the escape of the vohitile alkah; while, on tlie other hand, those things which clieck coagulation, sucli as cold and occlusion from air, prevent or retard the evolution of tlie gas. To the latter class he has added the remarkahle fact, that blood remains fluid for many hours under a liigh mercurial pressure, but coagulates when relieved from it. I confess that, although I was by no means pre- possessed in favour of this theory, these facts appear to me to prove irresistibly that the cause of the fluidity of blood, after it has been drawn from the body, is a minute portion of free ammonia holding the fibrine chemically in solution, and that the coagulation of such blood is the result of the escape of the alkali. The only point on vi'hich the evidence appeared deficient was the effect of occlusion from air in tubes of dead matter, and this defect 1 endeavoured to supply by the experiment which I mentioned at last meeting of the Society, by which 1 succeeded in keeping the blood of a slieep fluid for three hours within a vulcanised Indian rubber tube, the blood coagulating in about two minutes when let out just as if freshly drawn from the veins of the animal.^ Hence it appears to me that the medical profession is deeply indebted to Dr Richardson for his laborious and able investigations, which have, as I think, removed much mystery from this long vexed question. But Dr Richardson aims at much more than the explanation of coagulation outside the body. He believes that the fluidity of the blood within the healthy living vessels is due simply and solely to the presence of free anunonia, w hich he supposes to be genei'ated either in the systemic or pulmonary capillaries, and he denies that the walls of the arteries or veins have any effect on the blood by virtue of their vitality, or exercise any other influence upon it than that of checking ^ This experiment was performed in the following manner :—One of the jugular veins of a sheep having been exposed, it was emptied of blood by pass- ing the finger along it while pressure was applied by an assistant at its anterior part. Tiie vessel was then opened at two places about three inches distant from each other, and into each opening was tied one end of a piece of vulcanised India rubber tube, a quarter of an inch in diameter, and about eighteen inches long, filled with water, to prevent the introduction of air into the circulation. The pressure was then removed from the upper part of the vein, so as to allow the blood to flow through the tube. It was now easy to ascertain, by obsennng the collapse of tlie lower part of the vein, when a part of the tube was momen- tarily obstructed by pressure, that tlie circulation was going on freely through the new channel. This having been determined, ligatures of waxed string were tied as tiglitly as possible round the tube, at intervals of about two inches, beginning at the end next the head and proceeding backwards, so as to avoid all tension uj)on the enclosed blood, which was, of course, displaced freely in the direction towards the thorax. By this means a number of portions of blood were obtained enclosed in receptacles nearly, though not absolutely impermeable to gases. The various compartments were opened at different intervals, and up to three hours some of them contained fluid blood which coagulated on expos- ure, whereas there was in others a considerable portion of coagulum. After lour hours, coagulation was almost complete, but a .>^lender thread of fibrine wa.« still obtained from the fluid part in one of the divisions a few minutes afler it Jiad been let out.