50 Second Report on Rconomic Zoology. 
instance, it has little or no burning action on the leaves ; nor is it so 
easily washed off by rains. Moreover, I am sure it has considerably 
greater killing power, as is shown by the following experiments. 
Two are taken from recent records by Professor Webster in 
America, both carried out by different people, who are practical men, 
in their own orchards against Codling Moth ; the third was one of a 
series conducted by myself against Codling and Winter Moth. 
A. — In America. 
Treatment. 
Percentage of fruit 
harvested. 
/■Paris Green, J lb. to 50 gallons of water 
I Paris Green, § lb. to 50 gallons of water 
I. < Arsenate of Lead (weaker solution) .... 
I Arsenate of Lead (stronger solution) .... 
lUnsprayed ........ 
* 
61-65 
43-46 
74-98 
82-50 
43-67 
t 
63-04 
51-33 
81-63 
81-45 
49-09 
Treatment. 
Percentage of picked 
fruit injured. 
/Paris Green, £ lb. to 50 gallons of water 
j Paris Green, £ lb. to 50 gallons of water 
II. 1 Arsenate of Lead (single strength) .... 
1 Arsenate of Lead (double strength) .... 
lUnsprayed ........ 
* 
17-48 
12-87 
9-26 
8-30 
32-78 
t 
2-02 
3-10 
5-88 
3-43 
37-82 
B. — In England. 
Treatment. 
Percentage of fruit 
injured by maggot. 
(Paris Green, \ lb. to 50 gallons of water 
III. < Arsenate of Lead (single strength) .... 
lUnsprayed ........ 
X 
37-5 
20-5 
62-5 
X 
29-7 
15-5 
71-5 
* = Grimes’ Golden Apple ; f Ben Davis ; J Worcester Pearmain. 
These results show the benefit of this form of arsenical wash over 
Paris green for Codling Moth. At the same time I should point out 
that the trees sprayed by myself with the wash showed no marked 
symptoms of Winter Moth ; the unsprayed were much eaten. 
The method of mixing the arsenate of lead is given in the First 
Ileport, p. 28, but it may be pointed out that a little treacle may be 
added with advantage, about 1 lb. to the 16 gallons, which makes 
