Volume 1

The practice of medicine / by Thomas Hawkes Tanner.

  • Thomas Hawkes Tanner
Date:
1875
Catalogue details

Licence: Public Domain Mark

Credit: The practice of medicine / by Thomas Hawkes Tanner. Source: Wellcome Collection.

    35/692 (page 7)
    serum of blood removed from the vessels. This serum consists of a pale-coloured and waterv solution of albumen; haying a density ot about I02Q, being of alkaline reaction, and holding m solution many- important substances. The albumen is probably associated or combined with soda; and it is the plastic material from which the tissues of all parts of the body are nourished, and by which tne cells themselves grow. When deficient in quantity indications ot defective nutrition gradually become apparent. The fibrin probably arises from it , t l i + +i The attention of physiologists has long been directed to the discovery of the essential nature of this process of coagiiiation. The immediate cause of coagulation appears to be the combination of two substances contained in the liquor ^Q.-iigxnn\%—jihrino-])tastic substance allied in properties to globulin, and fihnmgen which resembles albumen. But the question—What is the cause ot the solidification of the fibrin, in blood both m and out ot the body ? is still one that cannot be answered with certainty, ihere are objections to every theory which has been propounded:--to that of John Hunter, that coagulation is an operation of life; to Hewson's, that the phenomenon is mainly due to the influence of atmospheric air; to Scudamore's, that it is greatly promoted by the escape of carbonic acid; to Draper's (a revived theory), that the fluidity of the blood during life is maintained by the muscular tissues picking out the fibrin, as it is solidified, for their nutrition; and to Richardson's (now withdrawn), that the evolution of ammonia is the essential cause of the change. Witbin the body coagulation is liable to be induced by escape from or stagna- tion in the vessels, by disease in their walls, by contact with diseased structures, by entrance into the circulation of morbid products, or by great elevation of the temperature of the body. After withdrawal from the vessels coagulation is favoured by warmth, free access of air, and the multiplication of points of contact (Lister).^ More- over, the subtraction of the influence of living vessels is, in all probability, largely instrumental in causing this phenomenon. It is difficult to give the exact chemical composition of the blood J since this fluid is not only altered in quantity and quality in disease, but it difl'ers in different individuals and varies in com- position from hour to hour in the same subject according to the amount and variety of food taken. The following table, however, may be regarded as indicating approximately the proportion of the constituents of healthy blood in looo parts :— Water 784 Oxygen. ) , Carbonic acid I dissolved in the fluid. Nitrogen . j H^matlr^^^^^^}^°^^^^^^^^^° ^'^^ corpuscles . . 131' Fibrin 2*5 Albumen 70*