June, 1922] 
MUENSCHER ABSORPTION OF SALTS 
General Outline of Experiments 
The experiments which are reported in this paper were undertaken in 
order to obtain data which might indicate whether or not there is any rela- 
tion between absorption of water and of mineral nutrients. The absorp- 
tion of water was determined by measuring volumetrically the amount of 
water lost from the containers. The absorption of salts was determined 
by analyzing the plants for total ash. It is realized that the measure of 
ash does not represent an actual measurement of salts absorbed. However, 
with a uniform solution and a uniform method of analysis, for a given 
species the results are comparable as far as relative values are concerned. 
Two series of experiments, summer and winter, were conducted in the 
greenhouse. In the summer series the rate of transpiration was reduced 
by increasing atmospheric humidity and by decreasing the intensity of sun- 
light. In the winter series transpiration was reduced by decreasing the 
light intensity and also by increasing the concentration of the nutrient solu- 
tion. Cultures were grown under the following conditions: 
I. Summer Series 
a. Dry chamber; standard Knop's solution^ (.14%). 
b. Humid chamber; standard Knop's solution (.14%). 
c. Sunlight; standard Knop's solution (.14%). 
d. Shade tent; standard Knop's solution (.14%). 
II. Winter Series 
e. Sunlight; dilute Knop's solution (.07%). 
/. Shade tent; dilute Knop's solution (.07%). 
g. Sunlight; concentrated Knop's solution (.28%). 
Materials and Methods Used 
Summer Series 
The chambers used for the dry and humid series of cultures consisted of 
large glass cases each 140 centimeters long, 70 centimeters wide, and no 
centimeters high, placed in the middle of a greenhouse room. The air 
was kept in circulation continuously during the daytime by a fan in each 
chamber. Fresh air was pumped into the chambers by a compressor which 
was attached to a motor outside the chamber. 
The atmospheric humidity in the humid chamber was kept high by a 
^ The following standard Knop's solution was employed as the basis for making up the 
nutrient solutions: 
Ca(N03)2 0.8 gram 
KNO3 0.2 gram 
KH2PO4 0.2 gram 
MgS04 0.2 gram 
FeP04 trace 
Distilled water 1,000 cc. 
Total 1.4 grams 
