THE ENCHANGE OF IONS 
Potassium Chloride. Experiment ii 
The series of solutions of this salt, thirteen in number, covered 
concentrations ranging from 32 to 4.16M X io~^ with a regular 
difference of 327kf X io~^ between concentrations. The experiment 
ran fourteen days. The results are shown in figure 11. 
The record of these solutions showed a quite remarkable similarity 
of behavior regardless of the concentration as is shown by the parallel 
course of the curves. The result is the more striking when it is 
noted that the solution curves not only parallel each other but very 
greatly resemble that of the distilled water control. No clear absorp- 
tion took place in any solution until a concentration of 224.M X io~^ 
was reached. In this concentration and the stronger ones, up to 
32oikf X io~^, there was slight absorption during the latter part of 
the period. In general the roots in KCl solutions may be said to have 
lost heavily for four days after which the net loss of ions still proceeded 
at a slower rate, at times with the maintenance of an equilibrium for 
several days. In a few cases slight gains of absorption over leakage 
were seen but generally the loss preponderated over the gain. In no 
culture did the total absorption approach in magnitude the total loss. 
The action of KCl solutions is strikingly Hke that of distilled water, 
differing, however, in that the higher members of the series bring 
about a less marked initial loss of ions from the roots. 
The growth of the primary roots showed a marked gain over that 
in distilled water in but one culture, 128M X io~^ In its effect on 
the growth of roots, KCl in the concentrations studied acted essentially 
like distilled water. 
Sodium Chloride. Experiments 12 and 13 
A comparison of the action of Na with that of K under the condi- 
tions of these experiments being desired, two experiments were carried 
out with NaCl. In experiment 12 thirteen solutions of sodium 
chloride were prepared ranging in concentration from 8 to 104^ 
X io~^ with a regular interval of SM X io~^ between members of 
the series. The experiment ran fifteen days. The curves are shown 
in figure 12. 
An inspection of the record of these cultures shows that NaCl is 
very similar in its action to several potassium salts. After an initial 
period of three days during which the roots in all solutions gave up 
ions an absorption phase set in which reached its maximum on the 
