1915] SCHREINER & SKINNER—GLYCOCOLL 451 
20.75 grams, against 21.60 grams for the glycocoll, an average 
increase of only 4 per cent. 
TABLE Ul 
EFFECT OF GLYCOCOLL IN CULTURE SOLUTIONS CONTAINING VARYING 
AMOUNTS OF PHOSPHATE AND POTASH AND 
16 PPM. NH; AS NITRATE 
GREEN WEIGHT 
2 Y OF CULTURE SOLUTIONS | 
{ i 
P.O; | NH, | K.0 | Pet bere ge 
ppm. ppm. ppm. gm. | gm. 
64 16 ° ¥ 32 1.45 
56 16 8 1.90 | 2.05 
48 16 16 2.40 2,25 
40 16 24 250 | 2.60 
32 16 3¢ 2.62 | 2,50 
24 16 40 ya, 2.65 
16 16 48 2.90 | 2.85 
8 16 56 2.30 3.00 
° 16 64 2.30 2.25 
The beneficial effect of glycocoll in the solutions given in tables 
I, If, and III was most marked in those solutions containing no 
nitrate (table I). The effect was very slight in solutions containing 
8 and 16 ppm. of NH, as nitrate, which indicates that the function 
of glycocoll in the nutrient solution is the same as that of nitrate; 
that is, that it seems to be absorbed by the plants and can take the 
place of nitrate in its effect on growth. 
A large number of other solutions containing larger amounts of 
nitrate, up to 80 ppm., were employed in this experiment. No 
beneficial effect from glycocoll was observed in any of the cultures; 
on the other hand, some slight reductions in growth in some of 
these solutions was noted, but there was no marked harmful effect. 
Absorption of nutrient salts as affected by glycocoll 
The absorption of nutrients from the various solutions was 
determined, as mentioned before, by analyzing the cultures for 
nitrates immediately at the end of each 3-day period, and the 
phosphate and potassium on a composite of the solutions from the 
four changes. The colorimetric methods for determining small 
