HEMOLYTIC SERA AND THEIR ANTITOXINS. 197 



II. The Antitoxin to Hemolytic Serum. 



A serum with antitoxic properties for the hemotoxin that we 

 have been considering in the preceding pages is easily obtained. 

 It is, in other words, a substance capable of protecting rabbit cor- 

 puscles from the destructive power of our hemolytic serum* This 

 hemolytic serum, as already shown, is toxic for the rabbit. When 

 injected in doses of 5 c.c. or thereabouts intravenously it kills almost 

 instantaneously. At autopsy clots bathed with reddish serum are 

 found in the heart and large vessels, which indicates that hemolysis 

 has taken place in vivo. Disseminated hemorrhagic effusions are 

 also frequently found in the kidney and muscles, particularly in the 

 psoas muscle. The hemotoxin when injected subcutaneously into 

 rabbits in a small dose produces no severe effect and animals treated 

 in this manner acquire an antitoxic power in their serum. 



The hemotoxin is injected two or three times, at intervals of 

 15 days, in a dose of from 2 to 3 c.c. The rabbits are then bled 

 12 to 15 days after the last injection. 



The antitoxic (antihemolytic or antihemotoxic) serum obtained 

 by this relatively short treatment is not, to be sure, very 

 powerful; it is sufficiently so, however, to permit a study of its 

 properties. 



The simplest experiment to demonstrate its antitoxic property 

 consists in adding a relatively large dose of freshly obtained anti- 

 toxic serum to a small amount of fresh hemolytic serum. To this 

 mixture is then added a small amount of rabbit blood. As a control 

 a mixture of hemolytic serum, normal rabbit serum and rabbit 

 blood is made at the same time and in the same proportions. 



If the dose of antitoxin is sufficient, no dissolution of corpuscles 

 takes place in the first mixture. In the second mixture, on the 

 contrary, containing the same close of normal rabbit serum instead 

 of antitoxic serum, the corpuscles are destroyed. 



In such an experiment a considerably greater dose of antitoxin 

 than of hemolytic serum (10 to 20 times) must be used to protect 



* We have already shown (see p. 175) that an antihemolytic antitoxin similar 

 to that described by Camus and Gley and Kossel for eel serum may be obtained. 

 The serum that we described opposed the hemolytic effect of hen serum. 



Metchnikoff has recently described an antispermatoxin (Annales de lTnstitut 

 Pasteur, 1900, No. 1). 



