Читать книгу The Body at Work: A Treatise on the Principles of Physiology онлайн

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There is a constitutional condition, fortunately rare, in which blood does not coagulate. A person subject to this abnormality is said to suffer from hæmophilia. It is alleged that this condition is due to deficiency of lime in the blood; and the deficiency of lime is said to be due to excess of phosphates. The subject suffers from phosphaturia. His kidneys get rid of the superabundance of phosphates by excreting them in combination with lime. If this explanation be correct, there is a chronic insufficiency of lime in the blood, because it is being constantly withdrawn in the process of removing phosphates.

The difficulty in the way of establishing a complete theory of the coagulation of blood increases when the phenomena of incoagulability are considered. Blood may be rendered incapable of clotting in a variety of ways. Leeches and other animals which suck blood have the capacity of rendering it incoagulable. If the heads are removed from a score of leeches, thrown into absolute alcohol, dried, ground in a pepper mill, extracted with normal saline solution, a dark turbid liquor is obtained. This liquor, after filtration and sterilization at a temperature of 120° C., injected into the veins of an animal, renders its blood incoagulable.