New York AGRICULTURAL EXPERIMENT STATION. 253 
“4. While no direct experiments were made to test this matter, 
it is still very probable that all the above-mentioned conditions 
hold true likewise of the foliage of the apple and the grape. 
“5. Applied to practical orchard conditions, these results mean 
that rain in the daytime and, probably, the dew first falling in 
_ the evening are pre-eminently the determining factors in the injury 
of copper fungicides to foliage, the mere presence of dew or rain- 
water on the leaves in the dark influencing this action to only a 
very slight extent. The outermost leaves on a sprayed tree being 
most exposed to dew, rain and sunshine are the first to suffer in- 
jury, those on the interior following in regular order the falling of 
the more exposed leaves toward the ends of the branches.” 
Il. Leaves and fruit secrete fluids which dissolve small amounts 
of copper hydroxide after which the dissolved copper salt finds 
its way into the cellular tissue and death results to the cells reached 
by the copper solution. 
Of these secretions Schander*’ says: 
“1. The plant secretes acids, and dissolves therewith small 
amounts of copper hydroxide, after which the dissolved copper 
salt works through the walls into the leaf cells and kills them. I 
found this mode of toxic action in Fuchsia and Oenothera. 
“2. The fluids secreted by the leaves react as alkalis as in 
Phaseolus multifiorus. I believe that the toxic action of bordeaux 
upon Phaseolus leaves must be ascribed to this condition, although 
I was unable to establish soluble copper salts in a secreted fluid 
in which I put a drop of equally alkaline reacting bordeaux mixture. 
These plants, however, secrete a very small amount of liquid, so 
that I could obtain this only drop by drop for my experiments. 
Alkalis, indeed, only act as solvents of copper hydroxide when they 
arenitiexcessi 
In 1891 Galloway*® conducted an experiment on the pear in 
which he found that injury came from the use of air-slaked lime 
instead of fresh lime. He lets the inference stand that all such 
injury comes from the use of air-slaked lime. Fairchild*® agrees 
with Galloway, as shown by the following: ‘““ Numerous cases have 
been recorded of serious injury to the foliage from its use. Weed, 
Gothe, Chester and Galloway have shown its occasional injurious 
*“Schander (53, p. 579). 
“Galloway (23, p. 40). 
“Fairchild (20, p. 26). 
