Volume 1

Lectures on general pathology : a handbook for practitioners and students / by Julius Cohnheim ; translated...by Alexander B. McKee ; with memoir by the translator.

  • Cohnheim, Julius, 1839-1884.
Date:
1889-1890
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on general pathology : a handbook for practitioners and students / by Julius Cohnheim ; translated...by Alexander B. McKee ; with memoir by the translator. Source: Wellcome Collection.

    482/554 (page 460)
    inasmuch as one dare not push the depletion beyond half the total blood-quantum without seriously endangering the animal's life, the solid residue of the blood cannot be reduced by more than half its normal amount. This, however, is a degree of anasmia which can hardly be surpassed in human pathology. If, after rendering an animal highly hydrasmic, either by one, or better by several, bleedings and salt-water injections, you allow a little time to elapse and then measure its blood-pressure, this will, as a rule, be found to have fallen below normal. The fall, however, must so influence the velocity of the blood-stream that the gain which would other- wise accrue from the lessening of the frictional resistance in the capillaries does not usually manifest itself. The beha- viour of the corpuscular elements of the blood shows no appreciable differences in simple hydraemia and in hydremic plethora. Thoma* has called attention to the fact that the dilution of the medium in which the colourless corpuscles float is decidedly favorable to their amoeboid movements. Whether the red blood-corpuscles are affected by the water- ing of the plasma, and if so to what extent, we are ignorant as yet; I have repeatedly satisfied myself that no alteration of colour or shape can be detected in them, even by employing very high powers. Moreover, the fact demonstrated by Quinckef that the unit of volume, or of weight, of blood in individuals suffering from nephritis or contracted kidney has sometimes a considerably lowered haemoglobin-contents as compared with normal blood, does not, as will be readily understood, allow any further conclusion to be drawn from it, so long as nothing is known of the numbers of the red blood-corpuscles contained in the blood in these diseases respectively. But you will be chiefly interested in the ques- tion—how is it as regards the excretion of water from the vessels ? The answer is very simple. In a dog made hy- draemic in the manner described there is neither an increase of secretion nor of transudation. Urine, saliva, bile, gastric and intestinal secretions, are not abnormally profuse ; the lymph-stream is nowhere increased, and in no organ or cavity of the body is a collection of liquid formed. * Thoma, ' Virch. A.,' lxii, p. I. f Quincke, 'Virch. A./ liv, p. 537.