XIV. THE PROPERTIES OF ANTISENSITIZERS AND 

 THE CHEMICAL THEORIES OF IMMUNITY.* 



BY DR. JULES BORDET. 



One of the most important problems in the study of immunity, 

 and it must be confessed one of the most difficult of solution, is 

 the specificity of serum. The problem is, of necessity, complex. 

 We have known for some time that the antibodies of immune sera 

 are specific in the sense that they affect certain substances and 

 do not affect others. But in addition to this specificity of action 

 we apparently must recognize a specificity of origin. For example, 

 a given sensitizer (amboceptor or fixateur) should be designated, 

 not only in respect to the blood corpuscles or bacterium that it 

 attacks, but also in respect to the animal species that has formed it. 

 Two sensitizers, both active against the cholera vibrio, but derived 

 in one case from the rabbit and in the other from the guinea-pig, do 

 not act exactly alike under all circumstances; the same statement 

 holds for antitoxic sera. We know, for example, that the duration 

 of a passive immunity given by a preventive serum varies, depend- 

 ing on whether the serum is derived from the same species as the 

 recipient or from an alien species. 



A study of antisensitizers is particularly useful as throwing 

 light on the specificity of sera, and particularly as to whether this 

 specificity is as absolute as would appear. It would seem, a priori, 

 reasonable to suppose that the law of specificity should be most 

 evident in dealing with these antisensitizers or, more generally 

 speaking, in dealing with anti-antibodies. In this instance we 

 deal with substances that are not only antibodies, but are specific 

 both as regards action and origin. It would seem reasonable, then, 

 that they should afford the most notable and instructive instances 

 of specificity. 



* Les proprie'te's des antisensibilisatrices et les theories chimiques de 1'immu- 

 nite". Annales de 1'Institut Pasteur, XVIII, 1904, 593. 



280 



