On blood letting : an account of the curative effects of the abstraction of blood : with rules for employing both local and general blood-letting in the treatment of diseases / by James Wardrop.

Date:
1835
Catalogue details

Licence: Public Domain Mark

Credit: On blood letting : an account of the curative effects of the abstraction of blood : with rules for employing both local and general blood-letting in the treatment of diseases / by James Wardrop. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    this is best ascertained by the time it requires to co- agulate. A firm texture of blood has been generally considered as a mark of strong action in the arteries, and as pointing out the propriety of abstracting it, and, on the other hand, when its texture is very loose, the utility of repeating venesection has been considered questionable. Soon after coagulation, blood separates into two xhe Se- substances, the crassamentum and the serum. rum. The Serum, or watery part, exudes through the pores of the coagulum, whilst the crassamentum contracts, leaving the sides of the vessel containing it, and preserving its form. The proportions of the serum and crassamentum are various. In healthy blood they are nearly in equal quantities ; whereas, in very stout and labo- rious people, and also during some inflammatory diseases, the crassamentum is in the larger propor- tion. The serum is a fluid of a pale straw colour, has a slight saline taste, is somewhat viscid, rather hea- vier than water, and mixes readily with it. When exposed to a moderate heat, it coagulates into a light straw coloured glutinous mass, and the same efifect is rapidly produced* by its sudden admixture with an equal quantity of boiling water. The part of the serum which is thus coagulated, its Albu- either by the application of heat, or an admixture of men. acids, possesses most of the chemical properties of the white of egg, and has been termed the albumen. When serum is coagulated by heat, there oozes Serosity. from the mass a small quantity of a viscid substance, 4