MISCELLANEOUS INSECTICIDE INVESTIGATIONS. 29 
Table XVI. — Sound and wormy apples from sprayed and unsprayed plats — Contd. 
Plat 
Treatment. 
Tree 
No. 
Condition of fruit. 
num- 
ber. 
Wormy. 
Sound. 
Total. 
Per cent 
sound. 
II 
Arsenate of lead (paste), 2 pounds to 50 gallons 
lime-sulphur solution. 
Plat total 
1 
2 
3 
4 
5 
6 
29 
12 
28 
13 
26 
26 
3.777 
2,399 
5,146 
3,833 
3,972 
4,757 
3,806 
2,411 
5,174 
3,846 
3,998 
4,783 
99.24 
99.59 
99.46 
99.66 
99.35 
99.46 
184 
23,884 
24,018 
99.44 
Chocks (unsprayed) 
III-V.. 
1 
2 
3 
4 
5 
6 
7 
8 
1,548 
3.208 
2,342 
2, 432 
2,635 
2,385 
2,902 
2,312 
3,907 
5,556 
5,682 
4,116 
3,722 
1,566 
2,197 
1,356 
5,455 
8,764 
8,024 
6,548 
6,357 
3,951 
5,099 
3,668 
71.62 
Plat total 
63.40 
70.81 
62. S6 
58.55 
39.64 
43.09 
36.94 
19,764 
28, 102 
47,S66 
58.71 
As will be noted in Table XVI, out of 29,269 apples from the plat 
sprayed with arsenate of calcium 98.79 per cent were free from cod- 
ling moth. The fruit examined on Plat II, 24,018 apples, sprayed 
with arsenate of lead, was 99.44 per cent free from the codling moth. 
The unsprayed trees yielded 47,866 apples, of which but 58.71 per 
cent were free from worms. 
It will thus be seen that the arsenate of calcium compared yery 
favorably with the arsenate of lead, and since it can be produced 
more cheaply than the lead arsenate it would appear to have distinct 
yalue. The foliage in Plat I was as healthy appearing as in Plat II 
throughout the season, and, further, the fungicidal yalue of lime- 
sulphur was practically the same, whether arsenate of calcium or 
arsenate of lead was used. While arsenate of calcium has not been 
sufficiently tested to recommend it for general use, yet it would seem 
that this arsenical will probably serve as a satisfactory and cheap 
substitute for arsenate of lead. Arsenate of calcium may be manu- 
factured either in the paste or powdered form or made at home in the 
paste form. 
HOMEMADE ARSENATE OF CALCIUM. 
Arsenate of calcium may be prepared at home from various chem- 
icals, the more important being arsenic acid and lime, sodium arsenate 
and calcium chlorid, sodium arsenate and calcium acetate, etc. 
Potassium dihydrogen arsenate may bo substituted for the sodium 
arsenate, but is more expensive and would have no distinct advan- 
tages over the latter. 
The logical way to make arsenate of calcium is by combining 
arsenic acid with lime, but at the present writing arsenic acid can 
