THE BLOOD. . 209 



success the blood of a lamb into that of a man. It was believed 

 that a great panacea had been discovered whereby not only blood 

 lost by hemorrhage could be replaced, but a cure effected for many 

 diseases and infirmities. Subsequent attempts proved such miser- 

 able failures that the operation was abandoned and even proscribed 

 by law. More than a century later it was revived, but only after 

 much experimentation upon the lower animals. 



The serum of certain animals possesses the property of dis- 

 solving the red corpuscles of another species of animals. The serum 

 of a dog destroys the red corpuscles of man; the haemoglobin is 

 dissolved out. The serum, besides its action on the red corpuscles, 

 is also active against the white corpuscles of the same animal, stop- 

 ping their amoeboid movements. The haemolytic action of the serum 

 is related to its poisonous action on microbes. The normal serum 

 of certain animals kills microbes, as the serum of the dog kills the 

 typhoid bacilli. The power to kill red corpuscles and microbes is 

 due to 'the presence in the serum of two substances, an alexin or 

 complement and an amboceptor. In transfusion this plays an impor- 

 tant part. 



The knowledge gained thereby was to the effect that, for the 

 operation to be at all successfully performed, blood of the same 

 species of animal should be used as the one on which it is performed. 

 It was only after the establishment of this rule that it appeared 

 possible to determine the value of transfusion and to make applica- 

 tion of it, with some degree of safety, to man. 



In practice there are two kinds o'f transfusion: (1) blood with 

 fibrin; (2) blood without fibrin. In using fibrinated blood the 

 stream is passed directly from the blood-vessel, either artery or vein, 

 into that of the patient. Usually the peripheral end of a vein of 

 the person furnishing the blood is united with the central end of a 

 vein of the patient. The tubing should have been previously filled 

 with a normal salt solution so as to exclude the entrance of air into 

 the circulation, for, if sufficient quantity of it be introduced, it will 

 be carried to the right side of the heart, where, by virtue of the 

 heart's action, a froth will be generated, the bubbles from which, 

 being pumped into the pulmonary arteries, arrest pulmonary circu- 

 lation and cause death. The danger of coagulation is, however, very 

 great. 



In using defibrinated blood the shed blood is first whipped in 

 an open vessel with a glass rod so as to separate the fibrin ; it is 

 then filtered, heated to the temperature of the body, and injected 



