THE MEASUREMENT OF ANTAGONISM 



\V. J. V. OSTERHOUT 



(with three figures) 



Attention has been called to the need of a quantitative criterion 

 of antagonism, and it has been shown that such a criterion is easily 

 secured by mixing equally toxic solutions. In this paper 1 mixtures 

 of more than two components were not considered. In order to 

 clear up more fully the confusion which still exists in regard to the 

 measurement of antagonism, it seems advisable to point out the 

 special advantages of this method for mixtures containing three 



more 

 The 



matter 



how many components are used. 2 (By the additive effect is meant 

 the effect produced when each salt acts independently of every 

 other, when its toxicity is neither augmented nor diminished by 

 the presence of other salts.) If antagonism exists, there will be 



mixtures 



The 



xpected 



purely additive is the best measure of antagonism. It is best 

 expressed as percentage of the additive effect. 1 



ermination 



for quantitative results. The best method 

 us to make this determination most readih 

 been said, the method of mixing equally tos 



As has 



determination simple and accurate, no matter how many 



ponents are used. 



me 



much more 

 e difficulty 



09TERHOU 



Bot. Gaz. 5SM78. 



■ When the toxic effect depends on ions, it may increase somewhat as the result 

 of mixing the solutions because the ionization is increased. But this effect is usually 



small and it may be calculated without difficulty. 



Botanical 



[272 



