102 BOTANICAL GAZETTE [FEBRUARY 
would be unsafe, therefore, to make any extended discussion of the 
results, although they are believed to be entirely consonant with the 
true state of affairs. So far as they go, they disagree with those of 
TABLE IV 
sey tk ge oF KOH anp NAOH upon GROWTH AND TRANSPIRATION OF 
RACT OF “ea hein LOAM. AVERAGE OF TWO EXPERIMENTS 
‘ Units. bd ges 
No. Solution Transpiration | Green weight sar geet ' 
x Untreated soil ext. 100 100 26.9 
2 Soil ext. plus pos KOH 182 160 39-5 
3 Soil ext. plus 25 NaOH 157 138 29.2 
previous workers in showing that both the absolute and the relative 
amount of transpiration was increased by the addition of KOH and 
NaOH in small amounts. In these small amounts the effect upon 
growth appears to be distinctly beneficial. The transpiration per 
unit of green growth appears to have been increased slightly where 
the hydroxids were added. 
The effects of pyrogallol and tannic acid were studied on plants 
grown in soil extracts. The addition to the extract of a soil, especially 
if it be an unproductive soil, of these substances which probably 
possess no nutrient value usually causes increased growth and greatly 
increased transpiration. The effects of small amounts of these 
substances is shown in table V, where the figures are the average of 
six experiments on soil taken from six different plots at one of the 
state agricultural experiment stations. 
TABLE V 
EFFECT OF PYROGALLOL AND TANNIC ACID ON SOIL EXTRACT. AVERAGE OF 
SIX EXPERIMENTS 
Jnits et gee 
: i T 
No. Solution Transpiration | Green weight — a pio 
weight 
I Control roo b gole) 109 
2 Soil ext. plus 5 parts per 160 10g 139 
million pyrogallol 
3 Soil ext. plus us 5 parts per 139 100 133 
million tannic acid 
