14 
Bouyoucos, Transpiration of Wheat Seedlings as Affected etc. 
Table IV. 
Density of Cell Sap as Determined by the Freezing Point Method. 
P. p. m. of Solution 
in which Plants Grew 
0.0 
93.5 
4500.0 
Freezing point 
of the Cell Sap. 
4.200° C 
4.190° C 
4.175° C 
Table V. 
Density of Cell Sap as Determined by tbe Electrical Resistance Method. 
P. p. m. of Solution 
in which Plants Grew 
93.5 
4500.0 
Resistance of Cell 
Sap in Ohms 
592.5 
411.9 
It is evident from botb tables that the density of the cell 
sap diminished with the decrease in density of the solution. It 
will be seen that in the first table the cell sap of the planfs grown 
in the highest density of solution lowered the freezing point 
.015° C more than that in the lower concentration, and .025° C 
more than that in the check. In the second table, tbe electrical 
resistance was 180.6 ohms less in the plant juice derived from the 
plants grown in the highest concentrated solution than in the other. 
Experiment II. This experiment was the same as the pre- 
ceding one except that in this case only the electrical resistance 
method was used to measure the density of the cell sap. The 
results obtained are given in the following table. 
Table VI. 
Density of Cell Sap as Determined by the Electrical Resistance Method. 
P. p. m. of Solution Resistance of Cell 
in Which Plants Grew Sap in Ohms 
93.5 
4500.0 
422.0 
210.9 
It will be observed that as in the foregoing experiment the 
density of the cell sap was decreased with the reduction in con¬ 
centration of the solution. 
These experiments were repeated also in sand cultures, and 
the data obtained w r ere identical as the above. 
Experiment III. In this experiment beans were used instead 
of wheat, the object being to see whether the above relation would 
hold true with other species. These plants were allowed to grow 
for 45 days in complete nutrient Solutions of 4500 and 750 P. p. m. 
Exactly 5.6900 grams of green weight were taken, the cell sap 
extracted as usual, diluted to 500 cc., and the density determined 
by the electrical resistance method. The table below contains the 
results secured in this case. 
