Myeloid tumour with complete absorption of the shaft of the humerus, following double fracture--excision--death / by Shirley Deakin.

  • Deakin, Shirley.
Date:
[1884]
Catalogue details

Licence: Public Domain Mark

Credit: Myeloid tumour with complete absorption of the shaft of the humerus, following double fracture--excision--death / by Shirley Deakin. Source: Wellcome Collection.

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    or face to the jugular vein ; or, in other words, must have passed through two capillary networks with their arteries and veins. It must, therefore, have completed an entire circulatory revolution. But to conclude that the time elapsing after the introduction of the salt into one jugular vein before it is found in the blood coming from the head in the opposite vein is the time required for one molecule of blood to pass from one of these points to the other, it must in the first place be admitted that the salt has been carried mechanically by the blood, without diffusing through it, with the same velocity as the blood itself; and in the second place to enable the formation of any opinion as to how often the entire mass of blood passes through the heart, it must be admitted that the velocity thus deter¬ mined by the infusion method is the mean velocity of the blood mass. To show that both of these assumptions are unwarrantable is the object of the present communication. I. The Element of Diffusion in Ilering’s Method—Poisseuille (Ann. d. Sciences Not., 1843, ii. ser. t. xix. p. 30) was the first, and as far as I? know has been the only one to offer any experimental proof as to the falsity of the belief that the potassium salt was carried mechanically, as would be an inert body, by the blood. He repeated Hering’s experiments on the horse, and was able to confirm his statement as to the time elapsing after the injection of the solution of potassium ferrocyanide before it ap¬ peared in the jugular vein of the opposite side; but he further found that this time was different for different substances, and was even modified by the presence of other substances when injected with the potassium ferro¬ cyanide. Thus, while the time required for the circulation of the potas¬ sium ferrocyanide was twenty-eight seconds in the horse, when a little alcohol, in quantity insufficient to have any appreciable effect on the pulse and blood pressure as measured with the huemadynamometer, was injected with the potash salt, the time of circulation was lengthened to forty-jive seconds. Or, when potassium nitrate or ammonium acetate was adminis¬ tered under similar circumstances, the duration of circulation was reduced to eighteen or twenty seconds. In other words, he found that in the living body the rapidity of circulation of substances mixed with the blood agreed with the rapidity of flow of the same substances through dead capillaries or even through glass tubes. It is, moreover, well known that if two fluids capable of mixing are brought into contact they will diffuse into each other with a considerable degree of rapidity, even when the mass of the liquid is at rest or when there is great difference in the relative volumes of the fluids ; while if one fluid is poured into another with which it is miscible, or if agitated after the two fluids are brought into contact, diffusion is almost instantaneous. And as some force is always employed in injecting the salt solution into the vein, the mixture of this solution with the blood will be promoted,