SPONTANEOUS ARREST OF HEMORRHAGE. 155 



person affected with the hemorrhagic diathesis, in whose blood 

 the fibrin is wanting ; and, as we have already seen in treat- 

 ing of transfusion, the vivifying effects of defibrinated blood 

 are equal to those of blood which contains all its constituents ; 

 yet it is provided that in hemorrhage the blood solidifies and 

 closes the opening in the vessels, if they be not too large. 

 She often makes attempts to cure aneurisms, or hemorrhoids, 

 by the same process ; and hence does not obliterate the vessels 

 by an organized substance, which would be capable of self- 

 regeneration and always remain as part of the body, but 

 throws out a temporary plug, which is destined to be re- 

 moved, partially, if not completely, by absorption. The pro- 

 cess of coagulation of the fibrin of the blood is essentially 

 different from that of gradual effusion of plastic lymph by 

 which injuries are repaired. Individuals suffering under the 

 hemorrhagic diathesis, are not deprived of the power of 

 repairing injuries by means of plastic exudations from the 

 blood, though the blood contains no fibrin, and hemorrhage 

 is not arrested until the process of repair has 'closed the 

 openings in the vessels, or we have closed them by the effect 

 of our styptics. We likewise see that in the lower animals 

 w T ho have not the means of artificially arresting hemorrhage, 

 its spontaneous arrest is more effectually provided for by a 

 more rapid coagulation of the blood. 



From the foregoing considerations it is evident that the 

 remarkable phenomenon of coagulation of the blood, whifch 

 has so much engaged the attention of physiologists, has rather 

 a mechanical than a vital function ; for its chief office is in the 

 arrest of hemorrhage. Coagulation never takes place in the 

 organism, unless the blood be in an abnormal condition with 

 respect to circulation. Here its operations are mainly con- 

 servative ; but as almost all conservative processes are some- 

 times perverted, clots in the body may be productive of injury, 

 as in the instances of cerebral apoplexy, clots in the heart 

 occtu'ring before death, the detachment of emboli, etc. 



