The Antagonism 'between Toxins and Antitoxins. 425 



injected with this heated mixture died, whereas the controls injected 

 with the mixture which had not been heated lived. From this he 

 concluded that the serum and venom were merely existing side by 

 side, and had not re-acted upon one another. In our experiments, on 

 the contrary, the rabbits injected with the heated and unheated 

 mixtures of venom and sernm alike lived, nor did any of them suffer 

 from symptoms such as loss of appetite, loss of weight, or diminished 

 temperature. The only conclusion to be drawn from these experi- 

 ments is that during the time which elapsed between the mixture of 

 the venom and serum the latter had acted upon the former, so that 

 there was no longer a fatal dose of venom present. The protocols- 

 will show that heating for ten minutes to 68 C. has no influence upon 

 the venom. (P. VI, experiment 4.) 



These results, while they lead to results in entire agreement with 

 those drawn from the filtration experiments with diphtheria toxin 

 and antitoxin, are diametrically opposed to the results obtained by 

 Calmette. As the experiments are so simple as not to leave any 

 possibility of experimental error, we turned our attention to any 

 existing difference in the conditions under which Calmette and our- 

 selves worked. As previously pointed out, Calmette absolutely 

 neglected the possible influence of time, temperature, and the relative 

 proportions of the active masses of the toxin and antitoxin present 

 in his mixture. Up to the present we have investigated the value of 

 the factors, time, and proportion of active masses, and have shown 

 that these are most important. Indeed, by altering either the one or 

 the other we can produce results which, if these factors be neglected,, 

 would lead to diametrically opposite conclusions. 



The toxin and antitoxin of this venom are both of great molecular 

 size and complexity. The former is a deutero-albumose and the 

 latter probably a globulin,* or at any rate its molecular size is of the 

 same order. A priori one would expect the velocity coefficient of any 

 reaction between such complex molecules to be a high one, and in 

 addition, from their great molecular weight, the solution will contain 

 relatively few molecules : so that it is not surprising that any 

 chemical operation in which they are concerned should occupy a very 

 appreciable time. 



The value of the factors time and influence of proportion of active 

 masses will be best seen in reference to the table below, which is 

 compiled from Protocols VII, VIII, IX, and represents the results 

 of twenty-one experiments. On reading along any horizontal line 

 will be seen the influence upon the result of the time during which 

 the toxin and antitoxin were allowed to operate upon each other y 

 with proportion of active masses constant. On reading any vertical 

 line the influence of varying proportions of active masses with time 



* Brodie, loc. cit. 



