152 LECTURES ON IMMUNITY 



astonishing, as many different substances destroy agglu- 

 tinins. For absorption it is, on the contrary, generally 

 possible to show that the absorbed bodies (e.g. dyes) exist 

 on or in the absorbing substance, from which they may 

 often be washed out. The authors have tried in vain to 

 poison animals by the injection of hydroxid of iron which 

 had been shaken with diphtheria poison or tetanospasmin, 

 which, just as agglutinins, are attenuated by such shaking. 

 If these poisons had been absorbed like agglutinins by the 

 bacteria, i.e. in a reversible way, then a strong poisonous 

 effect should have manifested itself in the injected animals. 

 But not a trace of the expected effect was observed. Biltz, 

 Much, and Siebert were then led to the conclusion that 

 the hypothesis of absorption is not tenable. 



They have therefore taken up an idea incidentally sug- 

 gested by Nernst for the explanation of the neutralisation 

 of toxins by their antibodies. This idea is not very differ- 

 ent from that of Behring. (Cf. p. 29.) Let us suppose 

 we have finely divided colloidal platinum (Bredig's "an- 

 organic ferment") and hydrogen peroxid. The peroxid 

 condenses upon the fine metal particles and thereafter it is 

 decomposed. This would correspond to the condensation 

 of a toxin, e.g. ricin, on the colloidal particles of its anti- 

 body, antiricin, and its subsequent decomposition. The 

 antiricin itself should be slowly attacked by the ricin, 

 just as the platinum, if it were oxidisable by the hydrogen 

 peroxid. This explanation is incompatible with the fact 

 that the ricin can be recovered after it is "neutralised," 

 therefore the neutralisation cannot depend upon its de- 

 struction. It seems that the advocates and adherents of 

 this idea (the schools of Nernst and of Ehrlich) had an 



