Rate of Absorption of Various Salts by Plant Tissue. 49 T 



Table VIII. — Carrot in Solutions of various Potassium Salts in Concentration 



N/50. 



Time in hours. 



Change in electrical conductivity. 



Potassium chloride. 



Potassium sulphate. 



Potassium nitrate. 



0-25 

 2 -25 

 19 -0 

 42 -0 



- 145 



- 233 



- 550 

 -1042 



-212 

 -258 

 -266 

 -311 



- 197 



- 214 



- 625 

 -1152 



3 



a 

 o 



a 



bC -1000 



a 





o K.sn, 





■ ^ 



















TIME IN HOURS 



Fig. 7. — Carrot in Solutions of various Potassium Salts of Concentration N/50. 



The difference between chloride and nitrate is small and no emphasis caii 

 be laid on it. The slight absorption of sulphate is very striking. 



From these results it may be concluded that the order in which kations 

 are absorbed at the beginning of the experiments is in general the 

 following : — 



K, [Ca, Na], Li, [Mg, Zn], Al, 

 although the nature of the anion may influence the order to some extent. 

 The anions are absorbed initially in the order SO4, NO3, CI. In both the case 

 of kations and anions this order alters in the course of absorption, owing to 

 the different position of equilibrium attained in the cases of the various salts. 

 The following Table shows the influence of the nature of the salt on the value 

 of the absorption ratio (i.e., the ratio between internal to external concentra- 

 tion of the salt or ion) after the absorption has proceeded towards equilibrium. 



