266 PROTEIN POISONS 



The Toxogens. There has been marked diversity of 

 opinion concerning the nature of the substance developed 

 in the body under the influence of the anaphylactogen. 

 Most German authorities, following the nomenclature 

 introduced by Ehrlich in his masterly studies of toxins and 

 antitoxins, have designated the sensitizing proteins as 

 antigen and the substance elaborated in the organism as 

 antibody. It is evident that if antigen be appropriate for 

 the sensitizing substance, the substance produced under 

 its influence must be the "antibody." We have already 

 expressed our opinion concerning the unfitness of the 

 word "antigen." The inappropriateness of the term 

 "antibody" is equally evident. The anaphylactogen, 

 instead of rendering the organism resistant to subsequent 

 injections, renders it more sensitive. It is true, as we shall 

 see later, that this increased sensitiveness may be a most 

 delicate and efficient means of subsequent protection. 

 It sharpens the agents of defence, but it does not blunt 

 the implements of attack. It prepares the body cells for 

 subsequent contests, but it does not disarm the invader. 

 It places in the hands of the defender more efficient means 

 of warfare, but it does not impair the equipment of the 

 attacking force. It is not a shield for protection, but a 

 sharpened sword for battle. 



The blood serum of an animal which has been treated 

 with a toxin, mixed in vitro with the toxin in proper propor- 

 tion, may be injected into a fresh animal without effect. 

 The blood serum of an animal treated with an anaphylac- 

 togen, mixed in vitro in proper proportion with the anaphyl- 

 actogen and injected into a fresh animal kills it. Surely 

 there is no justification for the use of the terms "antigen" 

 and "antibody" in explaining the phenomena of sensiti- 

 zation. Moreover, their employment confuses and misleads, 

 and in our opinion they should be discarded. However, like 

 many other terms improperly used in scientific research, 

 they have become so deeply engrafted into the literature 

 that they cannot be eliminated, but their inappropriateness 

 should be clearly understood. 



