blance between these two curves, but on the other hand 

 that they are very different to those found for the other 

 toxins before examined, especially in the absence of a 

 marked prototoxin zone. 



It must be taken into consideration that the minimal 

 lethal dose (T) was at the time of the first examination 

 0.0015 Cc. and at the present moment is 0.0027 Cc. 



In looking at the curves it will be observed that 

 there is a tendency to flatness in the upper portion. 

 This seems to indicate that a formation of prototoxoids 

 was probably taking place at the time of the examin- 

 ation of the toxin. We have therefore postponed giving 

 a detailed account of the experiments until the curves 

 had been examined again and at a time when it could 

 be supposed that the formation of prototoxoid had ad- 

 vanced to a considerable degree. 



One fact of great interest in connection with this 

 toxin is, that contrary to all others previously examined 

 it produced paralysis in guinea-pigs both after the in- 

 jection of a non lethal dose of pure toxin and after a 

 toxin-antitoxin mixture. 



The above mentioned curves are closely analogous 

 to those described in the preceding paper on Tetano- 

 lysin. We have thus been fortunate enough to find and 

 to examine a diphtheria toxin in a state well suited for 

 a thorough analysis. 



The details of this will be published as soon as our 

 experiments have been completed. 



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