374 COLLECTED STUDIES IN IMMUNITY. 



elements anchor the toxin even in a test-tube and neutralize the 

 toxin just as does the antitoxin. If he added crushed fresh guinea- 

 pig brain to tetanus toxin, he found that the brain substance anchored 

 the toxin in such a manner that not only was the supernatant fluid 

 robbed of its toxic action, but that the brain laden with tetanus 

 toxin also exerted no toxic effect. From this we can conclude that 

 a chemical union has taken place between constituents of the ganglion 

 cells and the tetanus toxin. This combination is so firm that it is 

 not broken up on being introduced into the animal body; as a result 

 the toxin remains innocuous. 



That this is really a specific reaction and not, for instance, merely 

 an absorption is shown by the fact that boiled brain, in which the 

 chemical groups in question are destroyed, is just as little able to 

 exert this action as the pulp of any other organ of the guinea-pig. 



In addition to this Ransom has shown that the brain of living 

 animals possesses the same toxin-destroying power. In view of 

 this it would appear that the objections made by Danysz, which 

 refer to the divergent behavior of the decomposed brain pulp, possess 

 no great significance. I will not deny the fact that the favorable 

 result achieved in tetanus is evidently due only to the coincidence 

 that the tetanophile receptors are present in large quantity in the 

 brain. Such a coincidence, of course, need not obtain for every 

 poison. If the organs endangered by the toxin contain only small 

 quantities of toxin receptors it will be found that with what are, 

 at best, very coarse experimental methods these receptors escape 

 detection. This is the case, for example, with botulism toxin and 

 diphtheria toxin. 



Such confusing chance occurrences can, however, be avoided 

 with certainty if one employs poisons artificially produced, poisons 

 which, owing to their mode of production, are directed against cer- 

 tain particular kinds of cells. The ha?molysins produced by injec- 

 tions of blood, spermotoxins, and numerous other cytotoxins may 

 serve as examples. In all of these cases it can positively be proved 

 that the toxin is anchored by the susceptible cells in specific fashion. 



The second point concerns that premise of my theory which 

 states that the same organs which possess a specific affinity for the 

 poison molecule are able to produce antitoxin. In this connection 

 the very neat experiments made by Romer on abrin immunization 

 should be mentioned. As is well known, abrin, the toxalbumin of 

 jequirity beans, is able to excite marked inflammation of the con- 



