The aortic system, anatomically and physiologically considered, with a view to exemplify ... the wisdom, power and goodness of God as revealed ... in Holy writ. The Warneford prize essay, for the year 1839 / by Edward Smith.

Smith Edward, 1818?-1874.

Date:: 1840

Credit: The aortic system, anatomically and physiologically considered, with a view to exemplify ... the wisdom, power and goodness of God as revealed ... in Holy writ. The Warneford prize essay, for the year 1839 / by Edward Smith. 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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$4(5 a yellowish coloured fluid is pressed out called the serum; thus dividing it into two portions, the red coagulam, or clot, and the serum.. If ^lo^ exposed to a freezing temperature, it may be stances, preserved without change, but separates immediately on bein^ thawed. Alkalies, even in very minute quantity, will prevent its coagulation, and the same occurs with some neutral salts. Fontana says, that if the poison of the viper, or, ticuna, be added to about twenty parts of blood, it prevents its coagulation, whilst if that of the viper be introduced into the system during life, it immediately causes coagulation. In persons dying from the effects of electricity, blows on the stomach, poisoning from hydrocyanic acid, opium, and belladonna, and also from certain diseases, as the plague, cholera, and certain malignant fevers, the blood is said not to coagulate. Exclusion of it from air, retards the process of coajulation, according to Dr. Babbington.* Except under the above circumstances, the blood always coagu- lates when drawn from the body, independently of temperature, rest, or motion, or the presence or absence of air or other gases. Causeof the As to the cause of this phenomenon, there have been nume- coagulatioa of the blood, pous theories. Hunter believed that the blood was possessed of vitality, and almost of intelligence; conceiving that when the blood was in the vessels, in its proper place, and under ordinary circumstances, during life, it remained fluid, and apparently homogeneous; but when it was removed from the body, being no longer of use, and not capable of performing any function, it spontaneously separated. Others maintained, that during the passage of the blood from a fluid to a solid state, heat is evolved, which is the cause of this coagulation. This opinion was warmly maintained by Gordon, Thompson, and ]\Iayer; but Dr. Davy and Schroeder-vander-kolk, have successfully opposed it; and it must be remembered that it is the effect of coagulation, and not the cause; and further, that heat would merely coagulate the albumen, not the fibrine. It has also been maintained, that its being simply left at rest would cause it ; * Med. Chirurg. Trims., vol. xvi.$