THE INJECTION OF CHEMICALS INTO CHESTNUT TREES 
15 
a reinjection, sometimes longer. The most marked example of this readi- 
ness of intake was a tree injected with para nitro phenol (i/iooo G. M.). 
This solution flowed into the tree steadily for 41 days without a reinjection. 
In this time 32^/2 liters went into the tree through two holes each one centi- 
meter in diameter. 
The rate of absorption of the solutions of organic compounds was much 
Fig. 4. Graph comparing rate of intake of trees injected during July with water, 
alkali metals, and organic acids. 
greater than the rates of absorption of the solutions of the alkali metals, the 
heavy metals, and water. 
The daily intake of the carbon compounds was extremely irregular. 
Sometimes the curves seem to indicate that for a short period the intake 
measured variation in the transpiration of the trees. 
The curves of intake of a single tree injected with LiOH 1/200, and those 
of 3 trees with LiOH 1/500, represented in figures 5 and 6, show how regular 
was the daily intake of the trees injected with alkali metals. These dia- 
grams also illustrate the fact, common to all the chemicals injected in these 
experiments, that the greater the concentration of the solutions the greater 
the intake. 
The colloidal solutions of metals were injected into small trees in April 
before the leaves appeared. All the solutions went in slowly but steadily. 
The healthy bark extract went into the trees more readily than the 
