2 THE BLOOD. 



made on the inferior animals, has been applied to the human subject; and it has been 

 ascertained that, in patients sinking under hemorrhage, the introduction of even a few 

 ounces of fresh blood may restore the functions for a time, and sometimes permanently. 

 The operation of transfusion, which consists in the introduction of the blood of one indi- 

 vidual into the vessels of another, was performed upon animals in the middle of the 

 seventeenth century, and was soon after attempted in the human subject. So great was 

 the enthusiasm with which some regarded these experiments, that it was thought pos- 

 sible even to effect a renewal of youth by the introduction of young blood into the veins 

 of old persons ; and it was also proposed to cure certain diseases, such as insanity, by 

 actual renewal of the circulating fluid. These ideas were not without apparent foun- 

 dation. It was stated, in 1667, that a dog, old and deaf, had his hearing improved and 

 was apparently rejuvenated by transfusion of blood from a young animal. A year later, 

 Denys and Emmerets published a case of a maniac who was restored to health by the 

 transfusion of eight ounces of blood from a calf; and another case was reported of a 

 man who was cured of leprosy by the same means. But the case of insanity, which was 

 apparently cured, suffered a relapse, and the patient died during a third attempt at 

 transfusion. It is almost unnecessary to say that these extravagant expectations were 

 not realized. In fact, some operations were followed by such disastrous consequences, 

 that the practice was forbidden by law in Paris in 1668, and soon fell into disuse. 



Transfusion, with more reasonable applications, was revived in the early part of this 

 century (1818) by Blundell, who, with others, demonstrated its occasional efficacy in 

 desperate hemorrhage and in the last stages of some diseases, especially cholera. There 

 are now quite a number of cases on record where life has been saved by this means; and 

 oftentimes, when the result has not been so happy, the fatal event has been consider- 

 ably delayed. 



Numerous experiments on transfusion in animals have been performed, with very 

 interesting results. Prevost and Dumas have shown that, while an animal may be 

 restored after hemorrhage by the transfusion of defibrinated blood, no such effect fol- 

 lows the introduction of the serum ; showing that the vivifying influence in all prob- 

 ability resides in the corpuscles. Brown-Sdquard has shown that, in parts detached 

 from the body, after nervous and muscular irritability have disappeared, these properties 

 may be restored for a time by the injection of fresh blood. He also made a curious ex- 

 periment in which blood was passed from a living dog into the carotid of a dog just dead 

 from peritonitis. The animal was so far revived by this operation as to sustain himself 

 on his feet, wag his tail, etc., and died a second time, twelve and a half hours after. In 

 this experiment, insufflation was employed in addition to the transfusion. 



It may be considered established that, in animals, after hemorrhage, life may be 

 restored by injecting the blood, defibrinated or not, provided it be introduced slowly, 

 without admixture with air, and not in too great quantity. In the human subject, es- 

 pecially after hemorrhage, the vital processes are sometimes restored by careful trans- 

 fusion of human blood, with the above precautions; remembering that a very small quan- 

 tity, three or four ounces, will sometimes be sufficient. 



of Blood. The determination of the entire quantity of blood contained in 

 the body is a question of great interest, and has long engaged the attention of physiolo- 

 gists, without, however, any absolutely-definite results. Among those who have ex- 

 perimented on this point, may be mentioned Allen-Moulins, Herbst, Fried. Hoffmann, 

 "Valentin, Blake, Lehmann and Weber, and Vierordt. The fact that the labors of these 

 eminent observers have so far been unsuccessful in determining definitely the entire quan- 

 tity of blood shows the extent of the difficulties to be overcome before the question can 

 be entirely settled. The chief difficulty lies in the fact that all the blood is not discharged 

 from the body on division of the largest vessels, as after decapitation ; and no perfectly- 

 accurate means have been devised for estimating the quantity which remains in the 



