ANTAGONISM 



127 



pendent of the other.) KJ is the increased growth due to 

 antagonism ; it is best expressed as percentage of JE or as 

 100. 



In the same way increased toxicity (when the mixture 

 is more toxic than either of the pure solutions) may be 

 expressed as JH -=- JE. This sometimes occurs, but it is 

 much less common than antagonism. 5 



TABLE VII 



MIXTURES OF EQUALLY TOXIC SOLUTIONS 



Wheat (growth during 30 days) (NaCl 0.12 M+CaCl 2 0.164 M) 



The percentages refer to molecular proportions; that is, 75 per cent. CaCla + 25 per cent. 

 NaCl means a solution in which 75 per cent, of the dissolved molecules are CaCl2 and 25 per 

 cent, are NaCl. 



As an illustration of this method the results given in 

 Table VII may be cited. In this case the growth in the 

 various mixtures was in part determined directly and in 

 part was calculated from results obtained by growing 



6 See page 177. 



