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\ REPORT OF THE ENTOMOLOGIST. 103 
SPRAYING THE TREES WITH ARSENICAL MIXTURES.—January 22, 
1879, Mr. J. S. Woodward, of Lockport, N. Y.,at the meeting of the 
Western New York Horticulttiral Society, held in Rochester, stated 
that, having sprayed certain of his apple trees with Paris green 
quite early in the season, just after the fruit had formed, to destroy 
the Canker-worm,* the trees thus treated bore perfectly sound fruit, 
whereas the rest of the orchard was badly infested by the Codling 
Moth (see Rural New Yorker, February 8, 1879). 
This important statement was not further verified until the spring 
of 1880, when Prof. A. J. Cook, of Lansing, Mich., sprayed some 
Siberian crab-apple trees on the 25th of May, and again on the 20th 
of June, with London purple, 1 tablespoonful of the poison (Lon- 
don purple) to 2 gallons of water. The results, as published in the 
Proceedings of the American Association for the Advancement of 
Seience for 1880, page 669, published in 1881, were admirable, and it 
was stated to be a perfect remedy, although no tabulated statements 
were given. Since 1880 Professor Cook has made many experiments 
with both Paris green and London purple, and does not hesitate to 
recommend spraying with either as almost a panacea. He recom- 
mends their use in the proportion of 1 pound of the poison to 100 gallons 
of water. 
The remedy was at first received with some disfavor on account of 
the supposed danger in its use. The objections were summarized by 
Professor Riley in the Farmer’s Review, during the fall of 1880, and 
in the American Entomologist for October, 1880 (Vol. III, No. 10, 
p. 244), but in these very articles he indicated his appreciation of 
the remedy, if it could be divorced from its seeming dangers. Later 
experience in fact has shown that where properly used the remedy 
is not at all dangerous. Analyses made of the calyces of a number 
of poisoned apples by Professor Kedzie at Professor Cook’s request, 
in 1880, indicated this fact. A striking note, howevers is published 
by Professor Forbes, to the effect that apples taken September 10 
from a tree sprayed September 3, and analyzed by Professor Me- 
Murtrie, each yielded .9 milligram of arsensic, ‘‘an amount such that 
74 apples would convey a poisonous dose.” This would indicate that 
fall poisoning possesses some danger on account of the cumulative 
effects of arsenic. 
Professor Cook has since published many articles on this subject, 
and seems to have met with the most perfect success in the applica- 
tion of this remedy. His perfect results and his broad and sweeping 
statements are not, however, perfectly borne out by the results ob- 
tained by other experimentors. For instance, compare the following 
statement made by Professor Cook in i886 with the results obtained 
in Ohio, Illinois, and California, and which are described in the fol- 
lowing pages, and it will be seen that while he deserves every credit 
for the part which he has taken in putting this truly valuable remedy 
before the public, he is probably not justified in giving the impres- 
sion that it is an absolute specific, or that he was the first to demon- 
strate its value for the purpose: 
** It will be remembered that six years ago at the Boston meeting 
of the Science Association, [ demonstrated the value of the arsenites, 
Paris green and London purple, as spécifics against the Codling Moth 
* The first suggestion of Paris green for the Canker-worm, so far as we can learn, 
was made by Dr. LeBaron, in hisSecond Illinois Report, 1872 (for 1871), p.116. The 
suggestion was adopted in Illinois as early as 1873,and the poison was used with 
goo success (seo Riley in Third Report U.S. Ent. Com., p. 192). —L. O. H. 
