Nov.27, 1916 Effect of Sodium on Absorption of Plant Food 413 
NITROGEN, POTASH, AND PHOSPHORIC ACID ABSORBED FROM THE 
NUTRIENT SOLUTION BY THE VARIOUS CULTURES 
The data so far given include the nitrogen, potash, and phosphoric 
acid stored in the seed. The analysis of 100 seeds for these substances 
gave the following results: 
Gram. 
Weight of 100 seeds (dry). 2. 45 
Nitrogen.0486 
Potash (K 2 0 ).0185 
Phosphoric acid (P 2 0 6 ).0242 
If it is assumed that each lot of 100 seeds is of uniform composition 
and weight, the amount of nitrogen, potash, and phosphoric acid ab¬ 
sorbed from the nutrient solutions by the various cultures can be deter¬ 
mined by deducting the above quantities from those found in the plants 
grown in the culture solutions. The data obtained from the various 
cultures, reduced to this basis, are given in Tables V and VI, and are 
presented graphically in figures 6 to 8, the last figure representing the 
mean of the two sodium-carbonate series. 
TabbE V .—Effect of sodium chlorid and sodium sulphate on the absorption of nutrients by 
wheat seedlings 
Sodium chlorid. 
Sodium sulphate. 
Culture No. 
Sodium 
chlorid 
added to 
nutrient 
Elements absorbed from solu¬ 
tion (in percentage of dry- 
weight of plants). 
Sodium 
sulphate 
added to 
nutrient 
Elements absorbed 
from solution (in 
percentage of dry 
weight of plants). 
solution. 
N. 
KsO. 
P2O5. 
solution. 
N. 
K 2 O. 
P2O5. 
P. p . m. 
O 
3* 1 
6-3 
i-.7 
P. p. m. 
O 
2. 8 
6. 0 
2. 0 
50 
3*3 
. 5-5 
i-7 
5° 
2. 1 
5- 7 
2. 1 
3. 
IOO 
3- 6 
5-7 
1.9 
IOO 
1. 8 
5- 6 
i-9 
4. 
200 
3*5 
5-9 
1 . 8 
200 
2-3 
6. 4 
1.9 
5. 
300 
3-6 
5-5 
1.9 
300 
2.4 
5*8 
1.8 
6. 
400 
3 -o 
4 * S 
i- 5 
400 
2. 2 
$• 7 
1. 6 
7. 
500 
3-5 
6. 6 
2. 1 
500 
2 . s 
5- 1 . 
1. 7 
8. 
I, OOO 
3*o 
5- 5 
I * 7 
I, OOO 
2. 2 
4. 0 
x*4 
The percentage of nitrogen absorbed by the young wheat plants does 
not appear to be measurably modified by the presence of any of the 
sodium salts investigated in concentrations up to 1,000 p. p. m. Sodium 
chlorid in this concentration does not affect the absorption of phosphoric 
acid measurably (fig. 6), but depresses slightly the percentage of potajsh 
absorbed. Sodium sulphate depresses the absorption of potash decidedly 
and of phosphoric acid slightly (fig. 7), while with sodium carbonate the 
depression in the absorption of both potash and phosphoric acid is very 
marked (fig. 8). The depressing effect *>f sodium carbonate on the 
