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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    into different parts of a living body, rest, like cold or air, might be supposed to be the sole cause of the coagulation oi the blood : yet it is not rest considered simply, but rest under certain circumstances, which appears to possess such a power; for motion given to the blood, out of the vessels, will not of itself prevent its coagulation; nor will it even in the vessels themselves, if all the purposes ot motion are not answered by it. Motion seems to retard coagula- tion ;*t yet we know for certain that blood will in time coagulate even in the vessels themselves, and under certain circumstances sooner, perhaps, than anywhere else: as, for instance, when there is a disposition to mortification. In this case we find the blood coagulated even in the larger vessels. I have seen a mortification come on the foot and leg, and when it had advanced only to a cer- tain degree, the patient died. On examining the parts above the mortified part, I found the crural and iliac arteries filled completely with strong coagulated blood: we may thence infer that the ten- dency to mortification in the vessels produced this disposition in the blood. W the coagulation should be supposed to have arisen from the blood being stopped in the large vessels at the mortified part, let us reflect that this cannot account for it: the same thing ought then to happen in an amputation, or in any case where the larger vessels are tied up. the blood are diseased, and consequently not possessed of a full power of life. Hence the great difficulty of assigning the real share which rest has in producing coagulation in these cases; for the effects which seem to arise from mere rest may in fact arise from the diminished vitality of the vessels. It is not rest considered simply, but rest under certain circumstances, which appears to possess such a power; but when we reflect further that rest out of body has a contrary effect (see note below) we may, I think, conclude, with Hunter, that rest does not of itself in the least assist the coagulation of the blood. It is difficult to conceive that rest can have opposite effects on the blood in and out of the vessels.] * This is motion given to it in a vessel, without any empty space, and having beads put into it, which are shaken. f [When blood is briskly stirred or shaken immediately on its effusion, it retains a homogeneous character, and apparently loses its coagulating properties : but this appearance is fallacious; for if blood thus treated be placed on a filter, the fibrin will become apparent. It has, in fact, assumed the solid form ; but being in a state of minute division, it is diffused through the turbid liquor, and thus escapes observation. {Davy in Edin. Med. and Surg.Jutirn. xxix. 244.) Indeed it is very probable that coagulation is really accelerated in such cases, just as it is by a more moderate agitation. To prove the latter point, three por- tions of blood being taken ; the first and third were moderately stirred with a stick for two minutes, while the second was allowed to rest. The two former concreted in 3^ to 4 minutes, the latter or second portion did not concrete till C minutes, and at the end of 8 minutes the coagulum was much less firm than that of the other two. (Tfiaekrah, p. 68.) Scudamore observed a difference of one minute. {Op. cit., p. 40.) Prater observed a difference, but it was not so con- siderable. {Op. cit., p. 18.) It should be noticed, however, that these experi- ments were made in open vessels, while those which were made in close vessels were much less decisive. Agitation promotes coagulation by bringing the inte- rior particles of the mass into contact with the sides of the inert vessel, which will necessarily have the effect of rapidly dissipating its residual vitality. It is en the same principle, that a small portion of crassamentum dropped into fresh- drawn blood accelerates coagulation.]