Ill 



next trito-toxin etc. The last very weak toxins were 

 called toxons. 



This classification arises from the circumstance, that 

 the investigation of the first examined toxin, that of 

 diphtheria, presents great difficulties. As it is usually 

 kept in solution, it deteriorates comparatively quickly, 

 and the curve of neutralisation of such a deteriorated 

 toxin is very complicated. Besides the prototoxin which 

 will be mentioned below, one phenomenon was especi- 

 ally conspicuous. A mixture of toxin with a compara- 

 tively great amount of antitoxin, injected on guinea- 

 pigs, showed quite special effects: paralysis and rapidly 

 disappearing oedema, which in guinea-pigs could not be 

 produced by toxin alone. On the other side it was not 

 possible, even when large amounts were injected, by 

 means of this mixture to produce the typical effect of 

 the toxin: acute death of the animal in a few days, or 

 a necrosis on the place of injection, if the dosis had 

 not been great enough to kill the animal. 



From the experiments of that time is was therefore 

 an obvious conclusion, that these two actions which 

 differed so much were not the consequence of only a 

 quantitative difference, but that the diphtheria toxin 

 really contained two different components, the toxin 

 and the toxon. 



Still the examination of a new diphtheria toxin 1 ) has 

 recently given a curve of neutralisation quite similar 

 to that of tetanolysin and it is of special importance, 

 that this toxin in contrast to all those previously exa- 

 mined, produced paralysis quite as well, when it is in- 

 jected alone in small amounts, as when its "toxones" 

 (mixtures with antitoxin) are injected. We are therefore 

 justified in concluding, that the toxones are not bodies, 



!) Dreyer and Madsen: Studies on diphtheria toxin. 



71 - 



