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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    poses of life, we may conceive that the loss of colour and this unfit- ness are effects of the same cause; but, upon further observations on this fluid, it will be found that it may be rendered unfit lor the purposes of life without losing its colour, and may lose its colour without being rendered unfit for life:* slowness of motion in the blood of the veins is one circumstance that causes the alteration; but this alone will not produce the effect, for I have observed above, that arterial blood put into a phial, and allowed to stand quiet, does not become dark; but rest, or slowness of motion in living parts, would appear, from many observations, to be a cause of this change in its colour. We know that the blood begins to move more and more slowly in the arteries; we know that its motion in the veins is slow in comparison to what it is in the arteries; we should therefore naturally suppose (considering this alone), that it was the slowness of the motion that was the immediate cause. Rest or slowness of motion, in living and probably healthy parts, certainly allows the blood to change its colour; thus, we never see extravasations of blood but they are always dark. I never saw a person die of an apoplexy, from extravasation in the brain, but the extravasated blood was dark ; even in aneurism it becomes dark in the aneurismal sac ; also when the blood escapes out of the artery, and coagulates in the cellular membrane, we find the same appearance. These observations respecting apoplexy struck me much. I con- ceived at first that the extravasations there must consist of venal blood; but, from reasoning, I could hardly allow myself to think so; for whatever might be the beginning of the disease, it was impossible it could continue afterwards wholly venal, especially when the blood was found in a considerable quantity; because, in many cases, great mischief was done to both systems of vessels, and the arteries once ruptured would give the greatest quantity of blood : but to ascertain this with more certainty, I made the follow- ing experiment. I wounded the femoral artery of a puppy obliquely; the opening in the skin was made at some distance from the artery, by a couch- ing needle; the blood that came from the small orifice in the skin * [Bichat's opinion respecting the deleterious effects of venous blood, has been already briefly adverted to. Dr. Kay, however, found that when venous blood was injected in small quantities into the arteries it did not destroy life, or mani- fest any directly poisonous effects. Hybernating animals continue to circulate black blood during the period of their torpidity, with the effect of rather increas- ing their muscular irritability. {Hall in Phil. Trans. 1832.) Mr. Owen found that in the kangaroo the ovum did not connect itfelf with the mother, or the chorion put forth any villi until the period of gestation had two-thirds elapsed, although the fcetus continued to grow during this time without respiration, or any office vicarious of it. {Phil. Trans. 1834.) In cholera, the blood in the arteries is perfectly black, and yet the functions of the brain remain perfect to the last, although undoubtedly the animal and vital functions are much enfeebled. Be- sides which, many other facts are mentioned in the present treatise which clearly require some modification of Bichat's doctrine, in order to explain all the phenomena which relate to this subject]