Feb. 19,1917 Arsenical Injury through the Bark of Fruit Trees 
301 
extent of injury. This introduces an experimental error that must not 
be overlooked. Iron arsenate and one brand of zinc arsenite (California 
Spray Co.) have been conspicuous in all the tests by the small amount 
of injury which they produce. Other brands of zinc arsenite have 
proved more injurious. It is obviously unsafe to make general state¬ 
ments about “ortho zinc arsenite” without naming the brand. Indeed, 
we have no assurance that different lots of any brand will always be harm¬ 
less. The same may be said of the lead arsenates. Even those manu¬ 
factured as pure diplumbic or triplumbic show some differences. Two 
arsenicals have quite regularly given severe injury: Calcium arsenite and 
arsenic trioxid. Arsenic trisulphid has usually given less injury than 
these and copper aceto arsenite still less, though more, as a rule, than the 
ortho zinc arsenites and most lead arsenates. 
Table IV .—Results of wounding and treating branches of Hibernal apple on June 23 1 
igiiy with different arsenicals to show their relative injuriousness. Those with even 
numbers were covered with a denial rubber dam and those with odd numbers were not 
(see p. 286 ) 
Extent of injury. 
60 gm. of chemical. 
Above 
bandage. 
Below 
band¬ 
age. 
10 gm. of chemical. 
Above 
bandage. 
Below 
band¬ 
age. 
Entire branch. 
_do. 
_do. 
.do. 
_do. 
.do_ 
11 inches. 
Entire branch. 
.do. 
-do. 
.do. 
.do. 
.do. 
.do. 
Streak to tip.. 
Entire branch. 
-do. 
.do. 
.do. 
Streak to tip.. 
Entire branch. 
.do.... 
.do. 
.do. 
.do. 
.do. 
None. 
.do. 
Entire branch. 
.do. 
.do. 
.do. 
Inches. 
44 
27 
29 
41 
29 
33 
4 
18 
22 
, 39 
6 14+ 
& i6-j- 
40 
29 
2 
5 
2 
S 
20 
3 
7 
11 
18 
12 
54 
12 
None. 
...do.. 
18 
11 
13 
19 
Entire branch. 
-do. 
-do. 
_do. 
_do. 
.do. 
-do. 
_do. 
_do. 
-do. 
-do. 
.do.... 
_do. 
.do. 
1 inch. 
18 inches. 
36 inches. 
Entire branch. 
_do. 
3 inches. 
Entire branch. 
Streak to tip.. 
12 inches. 
Entire branch. 
.do. 
Streak to tip.. 
None. 
.do. 
Entire branch. 
Streak to tip.. 
8 inches. 
Entire branch. 
Inches. 
<* 31 + 
14 
29 
25 
16 
13 
34 
8 
b 9 + 
18 
a 10 + 
13 
15 
6 
1 
1 
2 
6 
5 
3 
3 
5 
TO 
2 
9 
3 
None. 
Do. 
10 
5 
I 
No. 
Chemical. 
Arsenic trioxid. Baker... 
_do. 
Arsenic trioxid, Merck. 
_do. 
Arsenic trisulphid, Baker. 
_do. 
Arsenic trisulphid, Merck. 
_do. 
Calcium arsenite. Baker. 
.do.. 
Calcium arsenite, Merck. 
.do. 
Lead arsenate, diplumbic, Baker. 
.do. 
Lead arsenate, diplumbic, Swift. 
.do. 
Lead arsenate, triplumbic. Baker. 
.do. 
Lead arsenate, triplumbic, Grasselli. 
.do. 
Lead arsenate, technical, Merck. 
.do.... 
Copper aceto arsenite. Baker. 
.do. 
Copper aceto arsenite, Ansbacher. 
.do. 
Zinc arsenite, ortho, California Spray Co. 
.do. 
Zinc arsenite, mixture. Baker. 
.do. 
Zinc arsenite, mixture, Merck. 
.do... 
a No. 1 (10 gm.) and 11 (10 gm.) grew from the same main limb and the streaks ran together on it. 
& No. 9 (10 gm.), 11 (10 gm. and 60 gm.), and 12 (60 gm.) grew from the same main limb, and the streaks 
from all three bandages ran together upon it, making it impossible to say how much of the common 
streak was caused by any one of them. 
