242 REPORT OF THE HORTICULTURAL DEPARTMENT OF THE 
Injury from an arsenite may or may not differ from that caused 
by bordeaux mixture. In my own experience injury from the 
former, usually arsenite of lime, has followed almost immediately, 
within ‘a day or two, and consisted of a blackening of the parts 
damaged, the injured portions consisting of large blotches or a 
whole leaf and if only a part of ‘the leaf was affected the remain- 
ing portion withered. My attention has only been called to extreme 
cases and these Woodworth ‘and Colby” designate as the acute 
poisoning of arsenic and describe a chronic poisoning which more 
nearly resembles bordeaux injury. The following is their descrip- 
tion of the two forms: 
“ While paris green is entirely insoluble in pure water, it appears 
that as ordinarily used a certain amount of it does find its way 
into solution and thus enters the plant; and if very much goes in, 
the death of the part of the plant thus poisoned ensues. The most 
critical period seems to be the time during which the spray re- 
mains wet upon the leaf, and each subsequent wetting of the leaf 
from any cause, such as fog or dew, continues the danger. It 
has been demonstrated repeatedly that dry paris green can be 
placed upon a leaf in any quantity, and so long as the leaf remains 
dry no evil results will follow. After an application in the wet 
way, almost immediately, within twenty-four hours, a blackening 
of the leaf, or of parts of the leaf may occur, or the leaf may. 
entirely escape at that time, !but later, after a dew or fog, show 
the signs of the action of the poison; or again, there may be no 
blatkening of the leaf observed at any time, but the leaf may 
become prematurely yellow and drop off within two or three weeks 
from the time the application was made; showing that the poison 
which entered the plant, though not enough to kill it at once, 
deranged its functions to stich an extent as to cause this prema- 
ture dropping. These two forms of poisoning we have designated 
as the acute and the chronic poisoning of arsenic.” 
After having investigated every supposed case of injury from 
an arsenite of which I could hear in 1906, and after much corre- 
spondence with those who have had injury in previous years which 
they ascribed to an arsenite, I am quite convinced that there is but 
little injury from this source to apple foliage in New York. Practi- 
cally all of the growers in this State use lime to prevent arsenical 
injury, and with success. 
* Woodworth and Colby (64, p. 11). 
