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PRACTICAL METHODS IN IMMUNITY 



times called an intermediary body). This something is called the "complement." 

 It is by some called "alexine," by others cytase (Metchnikoff). The complement 

 cannot act upon and destroy an invading bacterium or cell unless the amboceptor 

 is present to make the necessary connection. The complement is destroyed by a 

 temperature of 56 C., so that, if we heat the serum from an immune animal to 56 C., 

 the complement it naturally contains is destroyed, and the amboceptor it contains 

 which is not injured by such a temperature, is incapable of destroying bacteria or 

 cells, unless we replace the complement which has been destroyed by fresh comple- 

 ment. This is done experimentally by adding the serum of a nonimmunized animal 

 which contains the complement, but no specific immune body (amboceptor) to the 

 heated serum. This is termed "activating," and a serum so treated is said to be 

 "activated." When an immune serum has been heated to 56 C., it is said to have 

 been "inactivated." 



FIG. 46. Receptor of third order, and of some substance uniting with one of 

 them. (Journal of the American Medical Association, 1905, p. 1369.) c, Cell recep- 

 tor of the third order an amboceptor; e, one of the haptophores of the amboceptor, 

 with which some food substance or product of bacterial disintegration (f) may unite; 

 g, the other haptophore of the amboceptor with which complement may unite; 

 k, complement; h, the haptophore; z, the zymotoxic group of complements. 



Antimicrobic sera are not as efficient in treatment as antitoxic ones. 

 It might be that if we could use homologous sera for treating man instead 

 of the usual heterologous ones from the horse better results might 

 obtain. 



It would appear that a more hopeful outlook will obtain by combin- 

 ing serum therapy with chemo-therapy, thus a combination of anti- 

 pneumococcic serum with sodium oleate seems capable of producing cura- 

 tive results which neither alone can bring about. 



Again, a combination of vaccination (active immunization) with 



