718 Glandei's 



sKhstancc scnsibilisatrice or fixattiir). Red l)lood corpuscles+heinolytic 

 am])Oceptor+coinpleinent form a hemolytic system! 



The hemolytic amboceptor is strictly specific, consequently it ^vill 

 combine by means of its cytophile group with its own antibody only 

 (red blood corpuscles). On the other hand, the complement, which 

 is present in all fresh serum, is not specific, hence it may be fixed by 

 various amboceptors in suitable complementophile groups. Thus the 

 complement will fix specific immune bodies that develop in the tissues 

 of infected animals under the action of bacteria; these immune 

 amboceptors attract the complement to the bacteria in ({uestion or to 

 the dissolved elements of their substance. Hence, if we add fresh 

 serum Avhich contains the complement in suitable quantity, to a mixture 

 of a suspension of bacteria or a bacterial extract+inimune serum, the 

 complement will unite with the amboceptor of the immune serum so 

 that the free complement disappears from the fluids. Now, if we sub- 

 sequently add to this fluid a mixture of hemolytic amboceptor+red 

 blood corpuscles hemolysis will not rcsnlt, because the necessary com- 

 plement has already been fixed by the immune amboceptors and the 

 free complement no longer exists. In this case, therefore, a fixation 

 of the complement by means of an immune amboceptor has occurred ; 

 in other words the complement has been diverted from the hemolytic 

 system; On the other hand if immune amboceptors were not 

 present in the first mixture, the complement remains free and can 

 therefore exert its corpuscle-dissolving properties on the subsequently 

 formed hemolytic system. These two cases may be expressed graphically 

 as follows : 



1. Bactei-ia+Iminuiie-Senim+Complement-f Hemolytic Amboceptor+Red Blood Corpuscles 

 (Ant i gen) (Immune Amboceptor) 



• z^ No Hemolysis (Complement Fixation) 



2. Bacteria-|-Normal Serum-1- Complpment+Hemolytic Aiiiboceptor-|-Red Blood Corpuscles 

 (Antigen) (No Immune ^■^■—^^^^^^^^^^^^■■^^^^^■■■^^^^^^^^^"■■■■ii"^"" 



Amboceptor) = Hemolysis (No Complement Fixation) 



Consecpently if hemolysis fails to occur, i. e., if the complement 

 is fixed, we may conclude that the fluid contains an immune amboceptor ; 

 since, however, the latter can fix complement only with the aid of 

 its antigen and since the antigen (bacterial suspension or extract) 

 is known, the further conclusion is justified that the fluid contains 

 an immune amboceptor which corresponds with this antigen and thus 

 originates from an animal which is infected Avith the bacteria in ques- 

 tion. For example, if glanders bacilli were used as antigen the com- 

 plement fixation which followed indicates that the serum possessing 

 the fixing property originated from a glanderous horse. Under opposite 

 conditions, for instance, if hemolysis is not prevented, the conclusion 

 is justified that the horse which furnished the serum is not affected 

 with glanders. 



According to the observations of Schiitz & Schubert, 

 Miessner & Trapp, the authors and others, the complement 

 fixation method for the diagnosis of glanders has already proved 

 itself very valuable. Its advantage consists in that the relative 

 amount of immune amboceptor in the serum to be tested can 

 be determined quantitatively and that the result of the test is 

 very evident. If, for instance, carefully and progressively 

 graduated quantities of serum are used wdth suitable amounts 

 of hemol}i;ic amboceptor and complement it is possible to de- 



