274 MICROBES AND TOXINS 



mouth, the tonsils, and the nasopharynx may be combated by 

 this bacteriotherapy, and already very encouraging observations 

 exist. For example, epidemic cerebro-spinal meningitis starts 

 from the nasopharynx, and there are meningococcus carriers 

 just as there are diphtheria carriers. It is the more important 

 to employ the lactic bacilli against the meningococcus from the 

 fact that in vitro the former antagonize the latter (A. Berthelot). 

 The bacterium most to be recommended for the purpose is 

 the Bacillus bulgaricus administered in powders and derived 

 only from young fresh cultures in liquid media. It is not 

 necessary to insist upon the inconvenience of the use of anti- 

 septic washes and to contrast with these the biological 

 disinfection produced by modifying the flora. 



Sera. 



Serotherapy means treatment by means of the sera of 

 immunized animals. It may be preventive or curative, or both. 

 The animal furnishing the serum has produced its own 

 immunity, i.e., it possesses active immunity. The animal 

 which receives such a serum acquires a passive immunity. 

 Serotheraphy is equivalent to the transfusion of antibodies. 



The antitoxins were discovered by Behring in 1890. 



Antitoxic sera are not the only therapeutic sera : by 

 immunizing an animal with the bodies of bacteria antibacterial 

 serum can be prepared : with such sera there may be 

 transfused bacteriolysins, agglutinins, bacteriotropins, in fact 

 all the antibodies they contain, but above all there is transferred 

 their property of exciting the reaction of the phagocytes. 



Certain antibacterial sera are also anti-endotoxic in the 

 sense that they are capable of neutralizing endotoxins. They 

 are best prepared as we have seen by intravenous injections of 

 the antigen. Finally, sera may be prepared against viruses 

 only slightly known or not known at all ; the preventive action 

 of serum in general may be disregarded. 



Antidiphtheria Serum. — This is a serum of horses 

 immunised against the diphtheria toxin. The treatment of the 



