A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer.

  • John Hunter
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer. 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.)

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    the vascular system being supplied according to the necessity it has ; though every part is not equally endowed with power, or dis- position to make use of that power. The arteries, upon the whole, may be said to possess considerable living powers, and to retain them for a long time. This is evident when we observe what must happen in transplanting a living part of one body with an intention that it should unite with another body and become a part of it; the part transplanted must retain life till it can unite so as to receive its nourishment from that into which it has been inserted. It is, however, to be supposed that in such situations life can be retained longer than in others, although it is well known that it is preserved in the vascular system, even when there is no collateral assistance. I found in the uterus of a cow, which had been separated from the animal above twenty-four hours, that after it had been injected and allowed to stand another day, the larger vessels had become much more turgid than when I first injected them, and that the smaller arteries had contracted so as to force the injection back into the larger.* This contraction was so obvious that it could not but be observed at the time, which was forty-eight hours after the separation from the body of the animal. This shows, too, the muscular power of the smaller arteries to be superior to that of the larger, and that it is probably continued longer after the separation from the body; a property which the involuntary muscles possess to a degree greater than the voluntary, in the former of which classes the muscular structure of the arteries is to be considered. , To ascertain how long the living power existed in any artery after separation from the body, or perhaps, to speak more properly, after that communication with the body was cut off, by which we have reason to suppose life to be continued in a part, I made the following experiments, for which I chose the umbilical arteries, because I could confine the blood in them, and keep them distended for any length of time. In a woman delivered on the Thursday afternoon, the navel-string was separated from the foetus; it was first tied in two places and cut between, so that the blood con- tained in the cord and placenta was confined in them. The placenta came away full of blood; and on Friday morning, the day after, I tied a string round the cord about an inch below the other ligature, that the blood might still be confined in the placenta and remaining cord. Having cut off this piece, the blood immediately gushed out, and, by examining the cut ends of the cord, I attentively observed to what degree the ends of the arteries were open; and the blood having now all escaped from this portion, the vessels were left to contract with the whole of their elastic power, the effect of which * [The same fact is also proved by the great difficulty of thoroughly injecting the capillaries in a recently killed animal, so as to make the injection pass forwards into the veins. Thus also Wedemeyer found a much greater force re- quisite to force an irritating fluid, such as dilute alcohol or vinegar, through the capillaries of the living animal than when he employed a bland fluid.] 14*