196 
Smith and Butler. — Relation of 
If we pass now to a consideration of the relative absorption of and 
distribution of potassium in the plants we will obtain the results shown in 
Table VI. The data show that each plant growing in solution B absorbed 
0-9 mg. potassium from the solution, a negligible amount. The plants may 
be considered as having grown in the absence of potassium. The potassium 
absorbed by the plants growing in solutions A and C is practically identical, 
the increased concentration of calcium and sulphur in the latter having had 
no disturbing effect. It will be noticed that in all the plants, irrespective of 
the solution in which grown, the relative distribution of potassium in tops 
and roots is the same and is entirely independent of the amount absorbed. On 
the other hand, the total amount of potassium absorbed per gramme of dry 
matter formed is dependent on the amount available : the potassium require- 
ment for maintenance and the potassium requirement for growth are not the 
same. 
Table VI. Distribution of and amount of potassium in Blue stem Wheat 
plants grown 21 days in nutritive solutions A y B, C. 
Nutritive solution 
used. 
No. of I 
plants. | 
Amount of potassium 
in 
Tops. 
Roots. 
Entire 
plants. 
Potassium 
utilized per 
■ gramme dry 
matter 
formed. 
Tops. Roots. 
Total 
potas- Potassium j 
Ratio of sium absorbed 
potas- utilized from the 
sium p er nutritive 
content gramme solution 
°f of dry by one 
tops to matter plant, 
roots, formed. 
Mg. Mg. Mg. 
Mg. Mg. 
Mg. 
Mg. 
Mg. 
Nutritive solution A 
Nutritive solution C 
Nutritive solution B 
35 
20 
35 
311.20 104-00 415*20 
j 8o-io 56-50 236-60 
5.80 1*20 7-00 
74.26 
66-09 
6*43 
68-49 
61-92 
5-78 
1.08 
1*06 
1. 11 
72.73 11.76 
65.05 11.72 
6.31 0-09 
Experiment 2. In Experiment 1, it will be remembered, we found it 
necessary, in preparing the nutritive solution less potassium (solution B), to 
increase the calcium-magnesium ratio from 4-1:1 to 10-9 : 1. This was 
accomplished by simply adding calcium sulphate, and while no disturbing 
effect was produced, as we have seen, we nevertheless thought it desirable 
to determine whether one could equally satisfactorily prepare a less potas- 
sium solution of the same concentration and same calcium-magnesium ratio 
as solution A by simply reducing the amount of calcium sulphate used and 
increasing the amount of magnesium sulphate without introducing any 
disturbing effect. With this purpose in view we set up Experiment 2, 
using solution A and two new solutions modified in the manner indicated : 
a full nutritive solution (solution D) and a less potassium solution 
(solution E). Thirty plants of Blue stem Wheat were grown in each of the 
nutritive solutions A, D, and E. Five plants were grown in a jar and the 
seedlings were placed in the solutions when three days old. 
