Potassium to Growth in Plants. 
203 
nor to determine the dry weights directly. Furthermore, owing to the 
impossibility of separating the sand from the roots by lixiviation. the dry 
weights were obtained by difference as follows : The roots were dried and 
Table XIV. Green and dry weights of Early pedigree Dent field Corn 
grown in sand culture 59 days , both in the presence of and in the 
absence of potassium . 
Dry weight. 
Ratio of 
Nature of culture. 
No. of 
plants. 
Entire 
plants. 
Tops. 
Roots. 
tops to 
roots. 
Culture with potas- 
1 
4.7269 
3-958° 
0-7689 
5-!5 
sium present. 
1 
6-0507 
4.9792 
1-0715 
4.65 
1 
4.9487 
4.1896 
Q- 759 1 
5 - 5 i 
1 
57796 
4-9048 
0-8748 
5.60 
1 
4.6218 
3-8597 
0-7621 
5. 06 
1 
5-5393 
4.7709 
0-7684 
6-21 
1 
62657 
5.1724 
1-0933 
4-73 
1 
5.3620 
4.5222 
0.8398 
5-38 
Mean 
1 j 
5.4118 
4.5446 
0-8672 
5- 2 4 
Culture with potas- 
1 
°- 535 2 
0.4319 
0.1034 
4.17 
sium absent. 
1 
0-4616 
0.3614 
0-1002 
3.60 
1 
0-4272 
°-3483 
O.0789 
4.41 
1 
0.4124 
°- 334 2 
O.0782 
4.27 
1 
0-4221 
0.3326 
O.0895 
3 - 7 2 
1 
0.5169 
0-2550 
0-0619 
4.12 
1 
0.4636 
0-3620 
O.IOl6 
3-56 
1 
0.5360 
0.4312 
O.IO48 
4.11 
• Mean 
1 
0.4469 
Q- 357 1 
O.0898 
3 - 9 8 
Table XV . A mount of and distribution of potassium in Early pedigree Dent 
field Corn grown 59 days in sand culture free from and containing potassium. 
J 
No. of 
Potassium 
Ratio of 
Nature of culture. 
A mount of potassium 
utilized per 
potas- 
plants. 
in 
gramme of dry 
sium 
matter 
content 
formed. 
of tops 
T o P s. Roots, f***' 
Tops. Roots . 
to 
roots . 
Mg. Mg. Mg. 
Mg. Mg. 
Mg. 
Culture with potas- 
8 
2309.20 475.10 2784.30 
63.52 68.47 
0.92 
sium present. 
Culture with potas- 
8 
18.30 4-50 2 2 -8o 
6.41 6-25 
1-02 
sium absent. 
Total 
potas- 
sium 
Potassium 
utilized 
obtained 
per 
from the 
gramme pabulum 
of dry 
by one 
matter 
plant. 
formed. 
Mg. 
Mg. 
64.31 
347-19 
6.38 
2-00 
weighed in a platinum dish, ashed in a muffle furnace, and weighed again. 
The difference between these weights was assumed to be the weight of the 
roots. 
A consideration of the data presented in Table XIV shows that the 
