io8 IMMUNE SERA 



In order that isolysins may be formed, it seems 

 necessary to overwhelm the organism once or sev- 

 eral times with large amounts of cells or cell prod- 

 ucts of the same species; to produce, as Ehrlich says, 

 an ictus immunisatorius. Wassermann tried, by 

 using various blood poisons, such as haemolytic sera, 

 toluylenediamine, etc., for a continued length of 

 time, to cause the formation of these isolysins, but 

 without success, although in these experiments 

 each injection was followed by an appreciable 

 destruction of red cells and absorption of their 

 decomposition products. The gradual and even 

 repeated absorption of not too large quantities of 

 decomposed red cells does not therefore lead to the 

 formation of isolysins ; but, as already said, a sudden 

 overwhelming of the organism by large amounts 

 of the cells or their products is necessary. 



Multiplicity of Complement. The question 

 whether there exists in normal serum one single 

 complement which completes the action of the 

 various immune bodies, or, several complements, 

 some of which combine with bactericidal and 

 others which combine with haemolysins, etc., pro- 

 voked a large amount of discussion. 



Ehrlich as a result of his experimental work with 

 Morgenroth, claims that the latter is the case, viz. : 

 that it takes a different complement to fit the 

 immune body specifically haemolytic for guinea-pig 

 blood than it does to fit that specific for chicken 



