TOXIN AND ANTITOXIN 533 



the aldehyde group can unite with amido groups, hydrazin groups, 

 methylen groups, etc. In this group therefore the combining prop- 

 erty is not specifically limited, but extends to a large number of 

 combinations. On the other hand the one characteristic of toxins 

 and ferments is just this specific combining property. 



3. " The transformation of toxins into non-poisonous combina- 

 tions (toxoids), possessing the same affinity for the antitoxin is pos- 

 sible, but has not been definitely proven." 



I have already clearly shown that the doctrine of toxoids, now 

 generally accepted, is one of the best-established foundations in the 

 entire subject of immunity. However, with critics like Gruber, 

 who blindly condemn the views of others, one ought to be satisfied 

 if they recognize at least a possibility. 



4. " Toxin and antitoxin have feeble chemical affinities and 

 therefore unite with one another to form dissociable combinations or 

 perhaps molecular combinations in varying proportions. These con- 

 ditions explain the long incubation of the poisonous action and other 

 marked phenomena." 



To be sure the affinity between toxin and antitoxin may in some 

 instances be a feeble one, but this is by no means always the case. 

 The affinity between tetanus toxin and antitoxin is slight, and so 

 is that between complement and amboceptor. On the other hand, 

 however, there are poisons, such as diphtheria toxin and snake venom, 

 in which the reaction proceeds under strong affinities, so that the 

 process of neutralization takes the course of a straight line and not 

 of a curve. 



Gruber's statements might also give one the impression that 

 he is the first to introduce dissociation as an explanation of some 

 of the phenomena in immunity. I have always emphasized the 

 fact that amboceptor and complement are loosely bound, uniting 

 at high temperatures, but dissociating at low temperatures. 1 But 

 this is all wrong according to Gruber, 1 for a year and a half ago he 



1 I shall cite a passage from Ehrlich and Morgenroth's First Communi- 

 cation Concerning Hsemolysins (see page 7 of this volume), a passage which 

 Wechsberg has already called to Gruber's attention (Wiener klin. Wochenschr. 

 1901, No. 51). "This experiment clearly shows that under the conditions 

 present complement and immune body exist in the serum independently of 

 one another "; further also, " under certain circumstances the immune body 

 enters into a loose chemical union with the complement, one which is easily 

 dissociated." In view of this I cannot understand why Gruber still main- 



