ANTAGONISM 



155 



cisely determined. This is owing to the fact that S affects 

 only the speed of recovery (not the final level attained) 



2000 AMNUTES 



Fig. 67. — Curves showing the (calculated) values of S in 0.52 M NaCI, 0.278 M CaCh, and 

 in mixtures of tliese (the figures attached to the curves show the molecular per cent, of CaCl, 

 in the solution). The curves show the values calculated from constants obtained by trial 

 which are given in Table X. The abscissse represent the time of exposure to the toxic solu- 

 tion. The value of 5 at the start is in all cases 2.7. 



and, as the speed is variable, the most satisfactory pro- 

 cedure is to assume such values of Kb and Ks in 

 the equation^® 



= ^{k^^){ 



— KrT —KsT\ —KsT 



3 — e \ -\- Soe 



^Ks—Kb^ 



as cause the closest approximation to the observed speed 

 of recovery. The values of S thus obtained for each 

 solution are shown in the figure. In general, the speed 

 of recovery, as calculated from these values of S, is in 

 satisfactory agreement with the observations. 



By means of the equations already given and of the 



^'Cf. equation (3), page 103. 



