Ill 



diilerent from the toxins, bill thai they are Ihe same 

 toxin, diluted in diilerent degrees, the combinations of 

 toxin and antitoxin probably having no action at all. 

 With this we are far from maintaining, that all toxins 

 are homogeneous. On the contrary certain preparations 

 of diphtheria toxin give a curve of this form 1 ). 



Fig. 7. 



In this case it is the less toxic or perhaps the quite 

 atoxic part of the toxin, which is first neutralised by 

 antitoxin. The supposition seems necessary, thas this 

 preparation of diphtheria toxin contains two elements, 

 capable of fixing the antitoxin and of which the one with 

 the greatest chemical affinity hardly possesses any toxic 

 properties (Ehrlichs proto-toxoid), while the other (Ihe 

 toxin s.s.), allthough chemically weaker, is highly toxic. 



A somewhat analogous case seems to be that of 

 normal serum, described above; in small doses this 

 diminishes the toxic effect in the same manner as other 

 proteids, in greater doses it has a similar action as anti- 

 toxin. The most simple supposition is, that in the nor- 



l) Th. Madsen: Om Difterigiflens Konstitution. Overs, v. D. kgl. Danske Vidensk. 

 Selskabs Skrifter 1899. 



