PTA eA ES ST CE I ee ee 
orgy a a a ge eee a ee aa eae ea ae 
1910] SCHREINER & SKINNER—ABSORPTION AND GROWTH 17 
greatest effect, as is shown by the fact that the difference between 
the no nitrogen line and the 8 ppm. line is very great in the case of 
the nitrate, less in the case of the potash, and least in the case of the 
phosphate. As a rule, beyond the second or perhaps the third period 
the diagrammatic representation of the result is on the whole uniform, 
but is influenced undoubtedly by the conditions of growth during any 
P205 
all > ——— 
K,0 NH 
Fic. 8.—Showing the ratio of the original, the final, and the ratio of the loss of 
P,O;, NH;, and K,O from the culture solution in the third period. 
period; in other words, by weather and other conditions, which is 
shown perhaps the quickest in the nitrate removal from the cultures. 
Some remarks should here be made concerning the possible influ- 
ence of bacteria. In the course of these experiments bacteria and 
other microorganisms were excluded so far as possible, but no special 
effort was made to maintain absolutely sterile conditions, inasmuch 
as this would have been a practical impossibility in an experiment on 
so large a scale. Moreover, it may even appear questionable whether 
