May 12, 1923 IfijuTy to FoUagc by Arsenical Spray Mixtures 
521 
EFFECTS OF ADDING OTHER INSECTICIDES, LIME, ETC. 
In orchard, field, and garden practice it is often desired to add various 
substances to arsenical spraying mixtures. These substances are of 
various kinds: Other insecticides, or fungicides for combination sprays, 
soap, or other colloidal substances for an adhesive or “spreader*' on such 
plants as cabbage and sugar beet to retard the settling of the arsenical 
suspension, as recommended by Parker {22), or various materials to lessen 
the tendency to bum the foliage. 
UmE sui^phur 
The addition of lime sulphur to kill scale insects or to prevent apple 
scab is often desirable. This substance brings about a chemical reaction 
with most arsenical insecticides, and it is of interest to know whether the 
insecticidal and fungicidal properties of either or both are destroyed and 
whether the tendency to bum the foliage is increased or decreased. The 
first of these questions has been quite thoroughly discussed by Cordley 
(4) and Melander {18) and is hardly within the province of this paper. 
The effect of lime sulphur on the injury caused by the different arsenicals 
is shown in Table IX. The tests from which this table was prepared ran 
through three seasons and were carried on in four different parts of the 
State. Several brands of the chemicals were used. The arsenicals were 
used in such strengths as to contain either i or 2 grams of arsenic for 
each 2 liters of water. The lime sulphur (factory toiled) was added at 
the rate of 77 cc. of 28° Baum 4 in every 2 liters of mixture. If in 
any case the lime sulphur (control) alone caused injury, the series was 
rejected, but this was extremely rare. 
Tabi^E IX.— Effects of lime sulphur on the burning properties of variotis arsenical com¬ 
pounds 
Arsenical compounds to which 
lime sulphur was added. 
Number 
of 
brands. 
Ntunbcr 
of appli¬ 
cations. 
Number 
of times 
injury 
in¬ 
creased. 
- 
Number 
of times 
injury 
de¬ 
creased. 
Number 
of times 
the same. 
Number 
of 
times 
no 
injury 
with or 
without. 
Arsenic trioxids. 
2 
3 
2 
0 
I 
0 
Arsenic disulphid. 
I 
2 
2 
’ 0 
0 
0 
Arsenic trisulphids. 
2 
4 
3 
0 
I 
0 
Barium arsenate. 
I 
I 
0 
0 
I 
0 
Calcitim arsenites. 
3 
16 
2 
9 
3 
2 
Copper aceto-arsenite. 
2 
20 
12 
2 
2 
4 
Ferrous arsenates. 
3 
8 
0 
I 
0 
7 
Lead arsenates, triplumbic. 
8 
52 
25 
0 
I 
26 
Lead arsenates, diplumbic.... 
13 
85 
36 
0 
0 
49 
Lead arsenates, mixtures. 
10 
27 
15 
0 
I 
II 
Zinc arsenites. 
6 
42 
10 
3 
2 
27 
From Table IX it may be seen that lime sulphur causes an increase in 
the injury produced by most arsenical compounds. This is especially 
tme of copper aceto-arsenite, the lead arsenates and zinc arsenite. 
With calcium arsenite, however, it usually causes a reduction in the 
amount of injury, though not to such an extent as to make this compound 
