Feb. 19,1917 Arsenical Injury through the Bark of Fruit Trees 
295 
Table III shows quite conclusively that the injury through wounds 
of a few months or older is much less than through freshly made wounds. 
This has been tested at different times on branches other than those 
listed in this table, and it has been our general observation that while 
there is sometimes more or less darkening of the wood through wounds 
made several months or even two or three years before treatment, there 
is rarely any serious injury to bark or leaves. A few exceptions have 
been observed. 
Table III .—Results of treating branches of apple on July 15, 1912, with 25 gm. of 
Baker's calcium arsenite , to show the relative injury through wounds of different age 
and character 
No. 
Diameter 
of treated 
branch. 
Wounds under bandage. 
Extent and character of injury. 
1 
Inches. 
1 
Branch 1 inch diameter cut off 4 
A few lenticel spots. 
2 
1 H 
years ago. 
Branch cut off 4 years ago. Partly 
Slight discoloration on under side of branch under 
3 
iH 
healed. 
Branch i% inches diameter cut off 3 
bandage. 
Branch under bandage almost girdled by anasto¬ 
4 
2% 
years ago and completely healed 
over. 
Branch iha inches diameter cut off 3 
mosing lenticel spots. No special injury around 
wound. 
Practically no injury. 
S 
iH 
years ago. Partly healed. 
Bark peeled off S A by xA indies 3 
Indefinite streaking to partly killed side branch 2% 
6 
1 Vi 
years ago. 
Branch 1 inch diameter cut off 2 
feet above bandage. A few lenticel spots. 
No visible injury. 
7 
iVA 
years ago. 
Branch A inch diameter cut off in 
A few small lenticel spots under bandage. 
8 
iH 
winter of 1912. 
Branch cut off in late winter of 1912,. 
Nearly girdled under bandage. No special injury 
9 
2 l A 
Branch H inch diameter cut off 2 
around wound. 
N0 visible injury. 
10 
U 
months ago. 
Two twigs cut off 2 days before treat¬ 
Branch killed above and under bandage. Sunken 
11 
iH 
ment. 
Small branch cut off and notch cut to 
streak runs from each wound to tip. 
Branch killed above and under bandage. Sunken 
12 
1 
cambium 2 days before treatment. 
Twig and small branch cut off just 
before treatment. 
Twig cut off and notch cut to cam¬ 
streak runs to tip, 4 feet. 
Branch killed above and under bandage. Sunken 
13 
H 
streak runs to tip, 4A feet. 
Branch killed above and under bandage. Streak 
bium just before treatment. 
rims down 1 foot, injuring 3 side branches. 
PROTECTION OF WOUNDS BY PAINTING 
It was suggested in our preliminary report (10) that white-lead paint 
applied to wounds, even though they were freshly made and the arsenical 
was applied before the paint was dry, would offer some measure of pro¬ 
tection. This suggestion was based on very few trials, which left it in 
need of further investigation. Paint was therefore applied to wounds 
of various sizes and ages and these were afterwards treated with copper 
aceto arsenite or, in a few cases, calcium arsenite. More than 50 painted 
wounds were so treated. In some cases the chemical was applied as 
soon as the paint was put on and in others the paint was allowed to dry 
for different lengths of time. The wounds were made either by cutting 
off a small twig or by cutting a notch through the bark to the cambium. 
Seven wounded limbs were painted with white-lead paint and imme¬ 
diately treated with copper aceto arsenite. There was considerable 
