130 INJURY, RECOVERY, AND DEATH 



we might use mixtures of B with another solution of B 

 having the same toxicity as A. The two methods might 

 not give exactly the same result. This is an additional 

 argument in favor of using equally toxic solutions. 



An illustration of this method is found in the results 

 given in Table VIII. The growth in the various mixtures 

 (additive and antagonistic) was in part determined 

 directly and in part was calculated from results obtained 

 by growing plants in mixtures having almost the 



TABLE VIII 



MIXTUBES OP UNEQUALLY TOXIC SOLUTIONS 



Wheat (growth during 30 days) (NaCl 0.12 M+CaCk 0.12M) 



Culture aolution 



CaCl, 



Aggregate length of 

 roots per plant 



85 

 125 



195 



310 



380 



438 



300 



55 



Additive effect 



85 

 75 



66.5 



60 



58 



56 



55 



55 



Antagonism 



125-75 



75 

 195-66.5 



66.5 

 310-60 



60 

 380-58 



58 

 438-56 



56 

 300-55 



55 



= 0.67 

 = 1.93 

 = 4.17 

 = 5.55 

 = 6.82 

 = 4.45 



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

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

 25 per cent, are NaCl. 



same composition as the solutions given in the 

 table mentioned. 



For the sake of completeness it may be mentioned 

 that other types of antagonism curves are found; for 



