136 THE PRINCIPLES OF IMMUNOLOGY 



6000 c.c. of ox blood. The practical bearing of the disproportion of com- 

 plement to immune amboceptor lies in the use of bactericidal sera. It 

 is easily conceivable that injections of such sera may meet in the injected 

 animals' blood with an insufficient amount of complement for complete 

 activation. Therefore, it may be advisable in such experiments or in 

 therapeutic use of sera of this type to activate with a sufficient quantity 

 of fresh complementary serum. 



Normal Iso-hemolysins. Attention has been called (page 99) to 

 the phenomenon of iso-hemagglutination. Similarly iso-hemolysins 

 can be demonstrated. For such a purpose the serum must be fresh 

 and the corpuscles exposed to it at incubator temperature. It is prob-- 

 able that these hemolysins resemble other normal hemolysins. The 

 groups correspond to the groups of iso-hemagglutinins. As in other 

 experiments with hemolysins, agglutination appears and is followed 

 by hemolysis. Agglutination inhibits hemolysis to a certain degree, as 

 has been shown by Handel and by Karsner and Pearce. Kolmer, Trist 

 and Flick have maintained in a recent study that there are two varieties 

 of natural hemolysin and hemagglutinin in human sera. They find a 

 thermolabile variety of these antibodies which is destroyed at 56 C. 

 for thirty minutes and a less thermolabile or thermostable body which 

 is destroyed at 62 C. for thirty minutes. Exposure at 56 C. removes 

 the various iso-hemolysins but does not destroy the iso-hemagglutinins. 

 Sands and West have found that if the immune sera are filtered (more 

 particularly in I 10 dilution) through perfectly clean Kitasato or Cham- 

 berland filters a large amount of the hemagglutinin is removed, with 

 slight or no reduction of hemolytic activity. In fact, the hemolytic 

 activity may be increased by the filtration and this may be explained 

 as due to the removal of whatever inhibiting power on hemolysis 

 hemagglutination may display. 



Anti-amboceptors. Inasmuch as the bodies which take part in 

 hemolysis, the amboceptor and complement, are of protein nature, it 

 is presumable that they might serve as antigenic substances. It should 

 be possible to prepare anti-amboceptor and anti-complement. As pre- 

 viously mentioned, experiments have been reported which have been 

 interpreted to indicate that it is possible to produce such immune anti- 

 complements, but the evidence offered has not withstood criticism ; at 

 the present time it is extremely unlikely that true anti-complements 

 have been demonstrated. Anti-amboceptors were first produced by Ehr- 

 lich and Morgenroth who injected as the antigen a hemolytic immune 

 serum. If a hemolytic immune serum is injected in fairly large amounts 

 into an animal for whose red cells the serum is specific, death results. 

 By carefully-graded injections, however, it is possible so to immunize 

 the animal that it becomes immune to the toxic effect of the serum. 

 When so immunized the serum of this animal when added to a cell 

 amboceptor mixture and incubated will prevent subsequent hemolysis 

 on the addition of complement. Similarly anti-amboceptors may be 

 produced by injecting serum containing amboceptors into other animals 

 than those for which the serum is hemolytic. Ehrlich and Morgenroth 



