139 



I have not experimented with tobacco as the use of it is so well 

 understood that it seemed unnecessary. A few, however, report 

 unsatisfactory results with it, but it is possible that they did not use 

 it at tlie right time or in a proper manner. 



EXPERIMENTS WITH PARIS GREEN. 



Seven vine worms were placed on growing cranberry plants, and 

 ample time given them to web themselves up between the leaves ; 

 then, on June 22d, the plants were sprayed with Paris green in water 

 in the proportion of one pound to 200 gallons. The spray was a 

 very fine mist, and continued only until the plants were thoroughly 

 wet. On the next day two were dead, and on the following day all 

 were dead. An examination showed that Ihey were enclosed by the 

 leaves which were drawn together by their silk ; and that they had 

 eaten holes through the leaves, and when they reached the outside, 

 they ate some of the poison and weie killed by it. 



A, similar experiment was performed with seven other vine 

 worms on growing plants, but they were showered with Paris green 

 in water in the proportion of one pound to 300 gallons, and in two 

 days they were all dead. As these experiments were performed with 

 great care, and the insects very carefully watched throughout, there 

 could be no mistake in the matter. 



Wishing to ascertain what proportions of Paris green or London 

 purple in water could be sprayed upon cranberry vines without 

 injuring them, a plot of vines in the Insectary was sprayed with Paris 

 green in water in the proportion of one pound to 150 gallons, and a 

 similar plot with the same proportion of London purple in water, and 

 no injury whatever resulted to the leaves. There was no fruit on 

 these vines. 



Similar plots were sprayed with Paris green and London purple 

 respectively, in the proportion of one pound to lOd gallons, but with- 

 out injuring the leaves. 



A similar experiment was performed, using one pound of each of 

 the above poisons to 75 gallons of water, and this injured the leaves ; 

 the Paris green only a very little, while the London purple destroyed 

 about one-half of the leaves on the vines. 



