IV. ON THE MODE OF ACTION OF PREVENTIVE SERA.* 



By DR. JULES BORDET. 



Preparateur at the Pasteur Institut. 



{From the Laboratory of Professor Metchnikoff.) 



The properties of the blood serum of immunized animals are 

 being attentively studied. While it is still rather difficult to explain 

 the antitoxic properties in certain sera, our knowledge of the pre- 

 ventive power of serum, that is to say the property of immune serum 

 to protect animals against the invasion of bacteria, has recently 

 been greatly increased. In the present article we shall deal, not 

 only with certain new facts, but shall also review the conceptions 

 we have held and refer to the various opinions of other writers on 

 these subjects. We must repeat, then, not only those facts which 

 we personally have demonstrated, but also the researches of other 

 observers, notably of Pfeiffer and of Gruber. We shall frequently 

 refer to the work of Metchnikoff | whose experience and advice is 

 of such signal value to those who have the opportunity of working 

 with him. 



The attention" of many observers has naturally been directed to 

 those substances that are harmful for bacteria which the animal 

 body uses in its struggle against infections, and the presence of 

 which may be easily demonstrated, particularly in animals immu- 

 nized against the cholera vibrio. In such animals the serum is 

 endowed, not only with a preventive power but also with a distinct 

 bactericidal power for Koch's vibrio. One of the chief points of 

 disagreement is whether this bactericidal substance is uniformly 

 dissolved in the body fluids during life or is confined to cells. The 

 action of preventive sera on bacteria in vitro has been carefully 



* Sui 1 le mode (Taction des serums preventifs. Annales de l'lnstitut Pasteur, 

 1896, X, 193. 



f Particularly the article: RecheYches sur la destruction extracellulaire des 

 bacteVies, Annales de l'lnstitut Pasteur, June, 1895. 



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