IQ4 LECTURES ON IMMUNITY 



solution over which the mixture was placed in a test-tube. 

 If the mixture had been conserved for a certain time 

 (about half an hour at room temperature) there was 

 no indication that free toxin diffused ; but if the mixture 

 was used as it was freshly prepared, the toxin diffused 

 downward, so that the lower parts of the solid gelatinous 

 solution contained two lethal doses for guinea-pigs. Such a 

 strengthening of the chemical bonds is very often assumed 

 in the doctrine of immunity, and it corresponds really to 

 the phenomenon of Danysz. 



Therefore the strongly toxic solutions in which tetanoly- 

 sin has been added in fractions slowly lose their abnormal 

 toxicity, and after a time (about 6 hours at 37 C.) 

 they are no more toxic than the corresponding mixtures 

 which have not been fractionated. 



The results of the experiments of von Dungern regard- 

 ing diphtheria-toxin correspond in their general features 

 with those for tetanolysin, so that there is every reason to 

 believe that the cause is identical in the two cases. The 

 same may be said of the other cases in which Danysz's 

 phenomenon has been observed, but the experimental data 

 are extremely meagre. 



Portier and Richet observed a peculiar phenomenon, 

 which at first seems rather inexplicable, but which is very 

 similar to the phenomenon of Danysz, and therefore may 

 be interpreted in an analogous manner. They prepared 

 a solution of the poison contained in the filaments of 

 ccelenterates (Actinia or Physalis), which produces the 

 same effects as the poison of Urtica, by macerating these 

 filaments in glycerin and water. The poison was injected 

 into the veins of pigeons or dogs, and caused a deep sleep, 



