PROTEIN SENSITIZATION OR ANAPHYLAXIS 307 



animals in sufficient doses it kills within a few minutes 

 not after days. When repeatedly injected in non-lethal 

 doses the animal body does not elaborate an antibody 

 an antitoxin. Diphtheria toxin is specific; it is an exclusive 

 product of the diphtheria bacillus, and animals treated 

 with it in the proper way produce a specific antibody. 

 The cellular poison of the diphtheria bacillus is not specific; 

 the same poison is contained in other proteins, and it gives 

 rise to no specific antibody. We convinced ourselves 

 many years ago that the protein poisons and the toxins 

 are not related bodies, and we demonstrated that diphtheria 

 toxin gives no protection against poisoning with the active 

 substance contained in the protein molecules making up the 

 cell substance of the diphtheria bacillus. For this reason 

 we have never discussed the phenomena of sensitization 

 due to protein poisons in terms applicable only to toxin. 

 Years after we did this work Friedberger and Reiter 1 con- 

 firmed it by showing that the protein poison obtainable 

 from the cellular substance of the dysentery bacillus is a 

 wholly different substance from the toxin of the same 

 bacillus, but they make no mention of our work in this 

 connection, and they still call the protein poison a toxin 

 and speak of the antibody. 



It has been fully demonstrated that the protein poison 

 can be detached from its combination in the molecules of 

 specific precipitates, blood corpuscles, stroma, many bac- 

 teria, etc., by incubation with normal guinea-pig serum. 

 Other proteins require for their disruption and for the 

 liberation of the poisonous group, sera in which specific 

 ferments have been developed by sensitization. The 

 proteolytic ferment in normal guinea-pig serum is not 

 specific. It is capable of digesting many, but not all, 

 proteins. When a guinea-pig has been sensitized to a 

 given protein, its serum contains not only the general, 

 non-specific proteolytic ferment normal to it, but in addition, 

 the specific ferment. Whether the latter is a wholly new 



1 Zeitsch. f. Immunitatsforschung, 1911, xi, 493. 



