Se ee ee ee 
1910] SCHREINER & SKINNER—ABSORPTION AND GROWTH 27 
NitTRATE.—Table VI gives the results obtained for nitrate in the 
cultures containing different amounts of nitrate, similarly arranged 
and computed as in the phosphate table just discussed. 
TABLE VI 
SHOWING THE RESULTS OBTAINED FOR NH; IN THE CULTURES CONTAINING DIFFERENT 
AMOUNTS OF NH, (PPM.=PARTS PER MILLION) 
AVERAGE AVERAGE DECREASE OF 
PERCENTAGE | PARTS ‘PER NH 
on NE i MILLION OF CONNELL es NHs AverAGE | DECREASE PER 
IN NH; bad goat GREEN UNIT 0 
FERTILIZER IN encore WEIGHT GREEN 
MIXTURE SOLUTION ete ppm percentage WEIGHT 
100 80 70.2 9.8 52,2 2.752 Eien 
72 54-2 17.8 24.7 2.699 6.6 
80 64 42.0 2250 34.3 3.046 7-2 
70 56 32.8 4353 41.4 3.169 7.3 
60 48 24.1 2356 49.8 3-492 6.8 
50 40 18.3 207 54:2 3.685 5-9 
40 32 12.0 20.0 62.5 4.166 4.8 
30 24 6 59.9 74.6 3.852 4.6 
20 16 5.5 r5.5 96.3 3.893 4.0 
10 8 O:2 7.8 07-5 3.156 a6 
fo} fe) aS ee 0.995 er 
The green weight column differs from the one discussed in the 
phosphate table in that the highest result occurs with the 32 parts 
per- million NH, line, the numbers descending in each direction from 
his higher green weight. The change from o to 8 ppm. NH, is very 
marked in the green weight, which increases from approximately 
1.0 gram to 3.2 grams, an even greater change than was noted in 
the phosphate table. The average decrease in concentration was in 
this case greatest between the limits of 32 to 64 ppm., the increase 
being gradual from the 8 ppm. solution up to the 32 ppm. solution, 
then being practically uniform up to 64 ppm., when it again declines. 
The figures in the percentage decrease column are on the whole much 
greater than those in the corresponding column in the phosphate 
table, thus showing a comparatively greater decrease of the nitrogen 
than of the phosphate in solutions of equal content of these elements, 
respectively. The last column, showing the rate of decrease per 
unit of green weight, shows the same general tendency for these fig- 
ures to decrease with the decline in the original content of nitrogen 
in the solutions, as was noticed in the phosphate table, except that 
