28 BOTANICAL GAZETTE [JULY 
the first two results, namely in the 80 and 72 ppm. solutions, are in 
this case lower than the following three or four entries, while in the i 
phosphate table these two were the highest in the column. The 
conditions for growth with the phosphate in these two solutions, or 
groups of solutions, were very poor as compared with the rest of the 
results, while with the nitrate this difference in growth was not so 
apparent. 
Potasstum.—In table VII are given the results obtained for potas- 
sium, the table being arranged and the results computed in the same 
manner as with those in preceding tables. 
SS Nake es 
TABLE VII 
*SHOWING THE RESULTS OBTAINED FOR K,O IN THE CULTURES CONTAINING DIFFERENT 
AMOUNTS OF K,O (PPM.=PARTS PER MILLION) 
PERCENTAGE| ParTS PER | AVERAGE AVERAGE DECREASE OF K.0 
or K,0 MILLION OF | CONTENT OF K,0 AVERAGE DECREASE PER 
K.0 KON GREEN UNIT OF 
FERTILIZER : IN FINAL SOLU- WEIGHT GREEN 
MIXTURE SOLUTION TION (PPM.) ppm. percentage WEIGHT 
100 80 64.4 15.6 19.5 1.106 14.1 
go 72 54-1 17.9 24.8 1.922 0-3 4 
8a 64 40.6 a3%4 36.5 2.661 8.8 
70 56 36 EQ. 34-1 2.89 6.6 
60 48 28.9 ici 39.8 3.222 gy 
50 40 20.6 19-4 48.5 3-60 5-4 
40 32 11.5 20.5 64.0 3-929 5-2 
30 24 2 17.8 ae 3.577 4.6 
20 16 3-9 ¥2.t 75.6 3.535 3-4 
10 8 ss 4-9 61.3 3.172 1.6 
° ° ee = 1.978 Sve 
The green weight column is in its general tendency very similar 
to that observed in the nitrate table, namely that the 32 ppm. cultures 
give the highest green weight. The figures representing the avera 
decreases and percentage decreases, on the other hand, correspe 
in trend more closely with those shown in the phosphate table, | 
similarity being especially shown in the last column giving the 
of decrease per unit of green weight, in which a regularly descendin 
column of figures is seen. In the case of the green weight, the change 
from the 8 ppm. solutions to those containing no potash whatev 
was, as in the other cases, very marked, and this drop in green wei: 
was also distinctly noticeable in the solution where potash alone was 
present. The results given in the three columns in the tables show 
