GENERAL PROPERTIES*. THE CORPUSCLES. 387 



logical saline. If, however, one uses a lower concentration some of 

 the corpuscles are hemolyzed, and the number of corpuscles 

 destroyed and the rapidity of the hemolysis increase rapidly with 

 the lowering of the osmotic pressure. While a 0.7 per cent, solution 

 of sodium chiorid suffices in most cases for infusions and for diluting 

 blood, it does not entirely replace the normal plasma or serum, since 

 these liquids, in addition to the sodium salts, contain salts of 

 calcium, potassium, magnesium, etc., each of which has doubtless 

 a certain specific importance. In diluting blood outside the body, 

 when the dilution is large, better results are obtained by using what 

 is known as Ringer's mixture, which consists of the physiological 

 saline solution plus small amounts of potassium and calcium 

 chiorid. One formula for Ringer's solution is: 



Sodium chiorid 0.7 per cent. 



Calcium chiorid 0.026 " " 



Potassium chiorid 0.03 " " 



Hemolysis Caused by the Action of Hemolysins. It has long been 

 known that the serum of one animal may destroy the red corpuscles 

 of another animal. Thus, rabbits' blood corpuscles added to the 

 clear serum of a dog, cat, or man are quickly destroyed, with the 

 liberation of their hemoglobin. This action was formerly described 

 under the term tl globulicidal action of serum," and was compared 

 to the similar destruction, bactericidal action, exhibited by serum 

 toward some bacteria. In more recent literature the term hemol- 

 ysis has replaced that of " globulicidal action," and the hemolytic 

 effect that a serum may exert upon foreign corpuscles is attributed 

 to the presence in it of certain substances which in general are classed 

 as hemolysins. This hemolytic action is not due to a simple differ- 

 ence in osmotic pressure. The serums of the different mammalia 

 have all approximately the same osmotic pressure; the differences 

 are too slight to explain the effects observed. Moreover, if the 

 serum used is heated to 55 C. its hemolytic action is destroyed, 

 although no noticeable change occurs in the osmotic pressure. In 

 addition to the hemolysins found normally in the blood of different 

 animals it was shown first by Bordet * that they may be produced 

 artificially. The serum of guinea pigs has little or no effect normally 

 on the red corpuscles of rabbits' blood. If, however, one injects 

 into a guinea pig a little rabbits' blood and repeats the process several 

 times at intervals of a day or so it will be found that the blood of this 

 particular guinea pig has now a strong hemolytic action toward the 

 red corpuscles of rabbits. Moreover, the action is specific, that is, 

 the serum is hemolytic only toward the red corpuscles of the species 

 whose blood was injected into it. The process of producing a specific 



* Bordet, "Annales de lTnst. Pasteur," 1895. 



