300 THE BLOOD. 



more effective as oxygen-carriers ; this office is made still more 

 effective by keeping the corpuscles from becoming stagnant in the 

 capillary areas. 



In proportion as intravenous transfusion of salt solution has 

 come into favor for the treatment of hemorrhages, in a similar 

 proportion has transfusion of blood been abandoned. From what 

 has been said, it will readily be understood that in the withdrawal 

 of blood from the vessels of a lower animal or man the conditions 

 are most favorable for bringing about the destruction of leuko- 

 cytes, and the consequent setting free of the nucleoproteid pro- 

 thrombin. To throw this material into the circulation of a living 

 animal is to invite coagulation within the vessels, a condition 

 which is dangerous in the extreme, inasmuch as clots would be 

 inevitably carried into the smaller arteries of the brain, causing 

 embolism, and producing a fatal result. 



It has also been demonstrated that the injection of the serum 

 of the blood of some animals into the circulation of others, as 

 that of man into the vascular system of a rabbit, destroys the red 

 corpuscles. This is the globulicidal action of serum. Such a result 

 might follow in the case of blood -transfusion, unless special care 

 was taken to select an animal whose blood did not possess this 

 action upon the blood of the animal on which the operation was 

 to be performed. 



Hemolysis and Bacteriolysis. The fresh normal serum of 

 the blood of a goat, an ox, a dog, etc., has the power to dissolve 

 the red blood-cells of a rabbit or guinea-pig. This is described as 

 the normal globulicidal property of serum. Such serum has also 

 the power of dissolving many species of bacteria ; this is its bacte- 

 ricidal property. Buchner attributed both of these to a substance 

 existing in all normal serum, to which he gave the name alexin. 

 In transfusing blood, therefore, in the treatment of hemorrhage, 

 the danger of destroying the red blood-cells exists, in addition to 

 the danger already mentioned. It should be said that Buchner's 

 idea of alexin has been much modified by recent researches ; it has 

 been shown that the action of two substances is necessary to bring 

 about hemolysis : an inter-body and a complement, the latter corre- 

 sponding to Buchner's alexin. This was shown by Ehrlich and 

 Morgenroth, who treated the blood of a guinea-pig with the serum 

 of a dog, the complement existing in the guinea-pig and the inter- 

 body in the dog. 



These authorities carried their observations still further and 

 found that normal goat serum would dissolve the red cells of both 

 guinea-pigs and rabbits, and that in this serum there were two 

 inter-bodies, one for the red cells of the rabbit and the other for 

 those of the dog, and that there were also two complements. Ehr- 

 lich believes that there are many substances of similar character 

 existing in the normal serum which have a hemolytic action. 



