by the Roots of Living Plants. I. 
1 7i 
Table III. 
Relative electrical conductivity of solutions of calcium chloride in which 
peas had been growing for different lengths of time. 
Concentration. 
Relative electrical conductivity after 
36 hours. 60 hours. 84 hours. 
N 
10 
0.05225 
0-053 
0.0524 
N 
100 
0*00669 
0*00716 
0-00722 
N 
1000 
0.000707 
0.000745 
- — 
A second 
series of experiments 
with peas 
Series 2. 
unequal absorption of ions from the solutions, by the roots of those plants, 
which was shown by the results of the first series. 
From these experiments it is clear that a concentration of calcium 
N 
chloride approximately — is the most satisfactory for experimental 
purposes, as the results with this concentration throughout were more 
uniform than those obtained with the more dilute solutions ; further, toxic 
effects were apparently postponed until the plant had been growing in the 
solution for three or four days, whereas, with the more dilute solutions, the 
harmful effects, indicated by the irregularity of the results, appeared before 
sixty hours had elapsed after the cultures were started. 
Accordingly, in later experiments the plants were all grown in calcium 
N 
chloride solutions of approximately — concentration. 
Series 3. Maize plants which had been growing in tap-water for about 
a fortnight were used for these experiments ; the plants were divided into 
three sets, each set consisting of six plants, and the plants were removed 
after they had been growing in the experimental solutions for 23, 48, and 
57 hours respectively. A large percentage absorption was obtained in 
every case ; approximately the same amount of chloride was absorbed by 
each set, so that equilibrium is evidently reached very quickly ; in the case 
of calcium, equilibrium is reached before 48 hours have elapsed. The 
results are given in Table IV. 
Table IV. 
Percentage absorption of calcium and chloride by roots of Zea Mais from 
N 
solutions of calcium chloride . 
10 
Duration of 
experiment. 
23 hours 
48 hours 
57 hours 
Percentage 
absorption of 
calcium. 
i7-53±2-7 
25*28 + 1*04 
26*98 + 2.2 
absorption Oj 
chloride. 
6-512 +0*1227 
6*54 +0-2202 
5.875 ±0-2597 
