82 
The insecticide used was a compound of arsenate of soda and 
acetate of lead commonly known as the arsenate of lead. It was 
made by dissolving 123% ounces of the acetate of lead and 5 ounces 
of arsenate of soda in separate vessels, and pouring the two solu- 
tions, one after the other, into a barrel with 50 gallons of water. 
Two barrels were placed in the wagon at once, each with a No. 2 
Morrill and Morley spray pump carrying two lines of hose about 
twenty-five feet long, furnished with twelve-foot extension poles 
fitted with double Vermorel nozzles. 
In spraying, as high a pressure was used as could be kept up by 
hand ; and a fine mist of the spray was forced into the trees from 
every side, care being taken to wet thoroughly all parts of the 
foliage without causing the drops to run in streams upon the leaves. 
The varieties of apples in the orchard will be referred to in giving 
the results of the experiments. 
Three sets of experiments were made by spraying four, six, and 
eight times respectively, at intervals of about ten days, beginning 
May 6 to 10, and ending July 28. At the time of the first spraying 
at Carbondale, the apple-trees were in their first full bloom. 
Results of Experiments. 
As a basis for the discussion of the principal results of this ex- 
periment, I have prepared the accompanying table showing espe- 
cially the differences in quantity, number, and quality of apples 
borne, by trees sprayed and by those without treatment. This table, 
it will be noticed, is divided into two parts, an upper and a lower, 
and for convenience in reference I have numbered the vertical col- 
lumns from i to 12 and the horizontal sections of the table from 
I to 8. 
CuRCULio Spraying Experiments 
CI 
Columns 
1 
2 
3 
4 
5 
6 


Plot 
Times 
spray- 
ed" 
Trees used 
Apples picke 
Injured 
No. 
C't'd 
Date 
Bushels 
Number 
1 
I. Check] 
Exper. 

4 
■115 
111 
4 
4 
S. 16-20 
S. 16-20 
15.5 
23.9 
2,617 
3,308 
92.2 
28.59 
2 
II. Check 
Exper. 

6 
34 
32 
3 
3 
Jl. 26-29 
Jl. 26-29 
11.4 
16. 
2,593 
3,782 
21.4 
10 . 3 
3 
III. Check 
Exper. 6 
20 
20 
3 
3 
S. 17 
S. 17 
16.25 
22. 
2,770 
3,063 
1,540 
3.198 
95.6 
30.7 
4 
IV. Check 
Exper. 

8 
145 
119 
(9) 4 
4 
Jl. 15 
S. 16-20 
6.44 
24.44 
91.1 
18.5 
