TOXIN- ANTITOXIN REACTION 165 



respectively (the control animal with the same dose of 

 venom died in nine hours), but after fifteen minutes the 

 same mixture rendered the animal ill but it survived, while 

 after thirty minutes no toxic symptoms ensued. 



At one time it was stated that by electrolysis of toxin 

 small amounts of antitoxin are formed, but this is very 

 questionable. Electrolysis destroys the toxicity of toxins 

 by the production of acids, chlorine, and hypochlorites. 



Ehrlich's views have been opposed, principally on physico- 

 chemical grounds. Thus, Danysz, observed that if ricin or diph- 

 theria toxin be brought into contact with its corresponding anti- 

 body, the degree of neutralisation depends on the manner of 

 mixture. If the toxin be added to the antitoxin in two fractions, 

 allowing a considerable time to elapse between the additions, the 

 mixture contains a much larger amount of free toxin than is the 

 case when the whole (and same) amount of toxin is added at once 

 to the antitoxin. This phenomenon, known as the " Danysz or 

 toxone effect," seems inexplicable if toxin and antitoxin have 

 relations the same as a strong base and a strong acid. 



Arrhenius, Dreyer, and Madsen maintain that the phenomena 

 observed in the toxin-antitoxin reaction are explicable on the 

 hypothesis that the rate of reaction avidity of the toxin decreases 

 as antitoxin is added, that the interaction is a slow one, and that 

 different fractions of the toxin are progressively neutralised by the 

 added antitoxin, but more and more slowly. On these grounds 

 they consider that there is no reason to regard the diphtheria poison 

 as a highly complicated body. Whereas Ehrlich considers the toxin 

 and antitoxin to combine with great avidity, analogous to the 

 combination of a strong base with a strong acid, e.g. NaOH with 

 HC1, these critics believe the avidity of antitoxin for toxin to be 

 feeble, analogous to the combination of ammonia with boric acid, 

 in which as more and more acid is added, the amount of free 

 ammonia decreases, but more and more slowly, in correspondence 

 with a hyperbolic curve. The phenomena can be calculated accord- 

 ing to the law of " mass action," there being an equilibrium between 



Free NH 3 . Free H 3 O 3 B = y (NH 4 H 2 O 3 B) 2 



vol. vol. vol. 



where K is the constant of dissociation. The curve of the neutralisa- 

 tion of tetanolysin by anti-tetanolysin corresponds almost exactly 

 to the ammonia-boric-acid curve. 



