THE COAGULATION OF THE BLOOD. 271 diathesis in which the extraction of a tooth, the scratch of a pin, the slightest lesions, permit the most disastrous hemorrhage. In these, cases, pressure or ligation of vessels, if of sufficient size, affords only temporary relief. When the pressure is relieved, or the ligature comes away, the hemorrhage, of course, recurs. Ordinarily, however, the coagulating blood blocks the orifice in the wounded vessel, and thus checks further loss. The great vessels in the walls of the uterus, after the extensive lacerations of parturition, are stuffed by clots of blood and, further escape is thus, as a rule, prevented. Thus, also, successive layers of fibrin are sometimes deposited in the walls of a vessel, weakened and distended by disease (aneurism), so that the weakest places become the strongest by this adventitious padding. Unfortunately, fibrin sometimes exercises a more malign influence, in being swept off in the torrent of the circulation, from surfaces upon which it has become deposited, to distant places, to block up most important vessels. Masses of fibrin (emboli) are thus occasionally detached from valves of the heart, upon which they have come to be deposited, in consequence of the roughening induced by endocardial inflammations, and carried to plug the great vessels feeding the brain, and thus cause the most serious lesions, and often death. Here, then, we must conclude our brief survey of the properties of the blood. And whether we look upon it in the light of its mere complexity of construction, of the grave symptoms induced by even its partial loss, of its speedy reproduction after hemorrhage, of its maintenance of itself under the constant consumption which it must suffer, we can not fail to appreciate its importance. Magendie says that a celebrated physiologist became so convinced of the value of the blood as to define life as "the contact of arterial blood with the organs of the body, especially with the brain." If he had said, the consumption of the blood by 272 THE BLOOD AS THE SOURCE OF LIFE. the organs, and liberation of its latent force, he would have told all the truth. The older physiologists were fond of locating life as a peculiar principle or essence in the blood. It lodged in the pure or arterial blood. It was the promulgation of this delusion, that the soul dwelt in the arterial blood, that cost Servetus his life. Such temerity as the attempt to localise the soul awakened the ire of the theologians, and at the instigation and by the order of John Calvin, Servetus was publicly burned at the stake in Geneva, and nearly every copy of his works was thrown into the flames. The older clinicians waged bitter war among themselves concerning the part the blood played in disease. The "humoral" pathologists maintained that the blood was the seat of all disease. Much of the popular conceit of our own times regarding "impurities" of the blood is derived from the doctrines of humoral pathology. The impurities, which we are called upon to treat, are, for the most part, impurities of the skin, animal and vegetable parasites, with which the blood has nothing to do, except to nourish their host. The real impurities of the blood are the acute infectious diseases, the germs of which breed in the blood, with characteristic fecundity, feed upon it, disorganise and corrupt it, so that: "The life of all his blood is touched corruptibly." The blood, as the source of life, has always been recognised as the maternal substitute of the body from which it is derived. The contract for the sale of the soul had always to be signed in blood. So Mephistopheles insists that Faust shall sign his compact with him with a pen dipped in his blood, because as he says of this subtle fluid-a saying to which we are now prepared to agree:-"Blut ist ein ganz besonderer Saft" (Blood is a very peculiar juice). |