162 



THE GYPSY MOTH. 



be always exercised in its use. About ten per cent, of the 

 men employed in spraying suffered more or less from arseni- 

 cal poisoning. Some appeared to be much more susceptible 

 to its effects than others. This subject is more fully treated 

 in Appendix F, where instances of the ill effects produced by 

 the careless use of arsenic are given. Numerous sensational 

 tales were promulgated in regard to the effect produced on 

 animals by eating grass or foliage poisoned with Paris green. 

 That there is no danger of serious results to the larger 

 domestic animals from ordinary spraying has been proved 

 by Prof. A. J. Cook's experiments.* He fed to his horse 

 and to sheep grass on which the poison had been allowed 

 to drop copiously from sprayed trees. We have frequently 

 fed a horse in the same way without any apparent harm to 

 the animal. A Medford milkman was accustomed to take 

 as a gift the grass which people feared to use, it having been 

 cut on lawns where the trees had been sprayed. This grass 

 formed the principal food of his cows during the summer and 

 they showed no ill effects. At one farm in Somerville, where 

 the trees were liberally sprayed, three cows suddenly died. 

 A suit was threatened, but on account of lack of evidence it 

 never came into court, f Several flocks of fowls were stricken 

 with sudden mortality immediately after the trees which hung 

 over hen yards had been sprayed. Fowls show a great sus- 

 ceptibility to arsenical poisons. It is a question, however, 

 whether the fowls were killed by eating poisoned caterpillars 

 or grass on which the spraying liquid fell, or whether they 

 did not die from some epidemic disease. The matter was 

 not fully investigated. One instance was noted where a hen 

 died just as the workmen walked into the yard to begin 

 spraying. The owner was immediately notified so that the 

 impression might be avoided that it was killed by Paris 

 green. J 



* Bulletin No. 53, Agricultural College of Michigan Experiment Station, August, 

 1889. 



t Cows have fed without apparent injury on grass under trees which have been 

 twice sprayed with arsenate of lead at a strength of fifteen pounds to one hundred 

 and fifty gallons of water. 



X If wild birds are likely to be destroyed by eating poisoned vegetation or poisoned 

 insects, the benefits derived from spraying must be largely discounted, as birds are 

 most useful as insect destroyers. 



