50 Biological, Chemical and Physical Characteristics of Milk. 



The red blood corpuscles however are again dissolved when to the heated, "inacti- 

 vated" rabbit serum, guinea-pig serum containing complement is added. Therefore, 

 whereas neither the amboceptor in itself, nor the complement in itself can dissolve 

 blood corpuscles, the combination of the two is capable of doing it. 



The action of the anti-body is specific for the substance which 

 induced its formation, on homologous antigen. Diphtheria anti- 

 toxin acts only on the toxins of the diphtheria bacillus, and not on 

 the toxins of the tetanus bacillus. The specificity is a very high 

 one, nevertheless it is only relative; that is, a similar, although 

 somewhat weaker action is exerted on related antigen, as compared 

 with the specific antigen. 



The chemical structure of the anti-bodies is unknown, and 

 they are generally designated according to the action which the/ 

 exert in the animal body. 



Anti-toxins neutralize toxins, agglutinins agglutinate (stick 

 together) animal cells and bacteria, and drag them to the bottom, 

 precipitins and coagulins produce precipitation in antigen solu- 

 tions, hemolysins dissolve erythrocytes, bacteriolysins dissolve 

 bacteria, cytolysins dissolve animal cells, etc. 



If anti-bodies are produced by injecting antigens into an an- 

 imal, then the animal is actively immunized against the antigen. 

 On the other hand, if another animal is injected with the produced 

 anti-bodies it is given a passive immunity. The active immunity 

 lasts for a long time, the passive immunity does not last beyond 

 several weeks. 



If anti-bodies are present in the blood in certain quantities 

 they are excreted by the milk gland, and may be demonstrated in 

 the milk. 



Ehrlich succeeded in proving the passing of anti-toxins into 

 the milk of anti-toxic immune mothers, by showing that young 

 mice from non-immune mothers acquired a high degree of resis- 

 tance against the toxin when they were allowed to suck actively- 

 immunized mothers. 



The passing of anti-bodies into the milk even in the presence 

 of passive immunity was proven by Ehrlich, Schmidt and Pflanz, 

 although the passage was only slight. The action of such milk was 

 15 to 20 times weaker than that of the blood. 



Similar to the action of the anti-bodies of the first order are 

 those of the uniceptors of the second order; for instance, bacterial 

 agglutinins and precipitins. The passage of agglutinins from the 

 blood into the milk has been demonstrated by Kraus, in goats which 

 had been immunized against colon-bacilli, typhoid and cholera. 

 The later works of Bensaude, Bertarelli, Bamberg and Briigsch, de 

 Blasi, Courmont, Cade, Figari, Maragliano, Eodella, Staubli and 

 others confirm the findings of Kraus. The agglutination value of 

 milk, as compared with blood, may be lower or identical, or it may 

 even be greater than that of the blood. As it has been found that 

 bacterial agglutinins may pass into the milk, so it also has been 

 proved that agglutinins against animal cells may do likewise. 



