318 TRANSACTIONS OF THE HORTICULTURAL 



don Purple and a white arsenic solution, a pound to 300 gallons. 

 Paris Green mixtures, on the other hand, of a pound to 100 gal- 

 lons did but slight injury, and a pound to 200, 250 and 300 gal- 

 lons did none at all. He concludes that Paris Green only should 

 be used, and this no stronger than a pound to 300 gallons of 

 water. These experiments, it will be noticed, are opposed to 

 the conclusion of Mr. Jabez "Webster that a pound of London 

 Purple to 160 gallons may be applied to the peach without de- 

 stroying the foliage. Mr. Gillette found white arsenic in a solu- 

 tion of one pound to 1,500 gallons of water strong enough to do 

 serious injury to the peach. 



Pear. I notice only a single experiment with the pear — one 

 made by Mr. "Weed in Ohio in 1888 — where a pound of London 

 Purple to 100 gallons of water seemed to be somewhat injurious. 

 The addition of half a peck of air-slacked lime to the mixture 

 had in his experience the advantage of partially protecting the 

 foliage. 



The fact may be worth noticing that Cook found the willow 

 uninjured by a single spraying with a pound of London Purple 

 to 100 gallons of water, while maple and elm were slightly dam- 

 aged by a similar application. In Gillette's experiments a pound 

 of arsenic to 200 or 250 gallons burned the edges of the elm 

 leaves a little. Box-elder was badly damaged by a solution as 

 weak as a pound to 400 gallons, and even one to 500 spotted and 

 scorched the edges of the leaves a little. The latter strength 

 burned badly the leaves of the honey locust, and it somewhat 

 injured the foliage of the silver maple, while one pound to 800 

 gallons badly scorched the poplar. These results simply empha- 

 size the conclusion that the use of arsenical solutions should be 

 abandoned for practical work. 



EFFECTS ON INSECTS. 



No new observations have been made with respect to the effect 

 of these poisons upon the apple worm itself. The habits of the 

 insect make it, in fact, certain that it can be poisoned only in the 

 young, larva state, before it has penetrated the apple. 



Numerous elaborate experiments made by myself last June with 

 the plum curculio, showed (1) that the beetle feeds freely on the 

 various parts of the blossoms of the peach and on the leaf and 

 fruit and on rose blooms and flowers of .the snowball and honey- 

 suckle. Peony blossoms, on the other hand, were not eaten at 

 all. Specimens taken in early spring showed that even dead 

 leaves might be eaten as a last resort. Poisons applied to beetles 

 in confinement demonstrated that leaves sprayed but once with 

 Paris Green or London Purple would kill practically all the bee- 

 tles feeding upon them within ten days. Even a pound of Paris 

 Green to 500 gallons of water, accomplished this purpose, the 



