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the bisulphide to evaporate, destroying thereby the aphides infesting- 

 the vines. This interested me greatly, because the melon louse, Aphis 

 cucumeris Forbes, is at times a most destructive i)est in parts of New 

 York and New Jersey, and one of the most difficult to deal with, owing 

 to the fact that the leaves are close to the ground and that they curl as 

 soon as seriously affected, making it simply impossible to reach them 

 all, even with an underspray nozzle. A lot of pot-grown plants be- 

 coming badly infested with aphides in the botanical laboratory, I made 

 a series of experiments, which were not recorded, but which deter- 

 mined that the liquid evaporated slowly, that it killed plant-lice very 

 readily, and that it killed plants with equal facility if used in any large 

 quantity. The appearance of the lice on cantaloupe and citron melons 

 in New Jersey gave me an opportunity of making experiments, and Mr. 

 Howard Gr. Taylor, of Riverton, N. J., kindly permitted me to kill as 

 many hills as mi ght be necessary to carry them on. I procured a dozen 

 wooden bowls thirteen inches in diameter and six inches deep, inside 

 measurement, and a series of small, graduated tumblers, in which "1 

 teaspoonful" and " 1 dram" corresponded. To get at the rate of evapo- 

 ration I poured 1 dram into a graduate and left it exposed; but placed 

 in a shaded spot. It required fifteen minutes to disappear completely. 

 Eleven badly infested hills were then covered by bowls, the vines being 

 crowded under when necessary, and 1 dram in a graduate was placed 

 under each. At the end of twenty minutes I lifted one bowl, found 

 that less than half the material had evaporated; that all theCoccinel- 

 lidae were dead, the small lice dying, and the Diabrotica, ants, aiid large 

 viviparous aphides were yet all alive. Ten minutes later there was 

 little change. At the end of three fourths of an hour, though scarcely 

 more than half the liquid was gone, all save a few of the mature, wing- 

 less, viviparous females were dead. In one hour there was yet liquid 

 in all the graduates; but all the aphides were dead, or appeared so, 

 To test the matter, all the hills treated were marked to be examined 

 later. Another series of infested hills was selected; but the experi- 

 ment was varied by using 2 drams of bisulphide in some cases, using 

 a shallow saucer in others, pouring the liquid on the ground in two 

 cases, and covering other hills with large square boxes, some of them 

 anything but tight. All coverings were left on for one hour, undis- 

 turbed. Examined first a square box covering a shallow saucer with 

 2 drams of bisulphide; found this all evaporated and every aphis 

 killed. The bowls covering the saucers in which 1 dram was used 

 showed like results. Two square boxes which were not tight, covering 

 graduates with 2 drams of liquid, had all insects unaflfected and the 

 material scarcely half gone. The two bowls under which the bisulphide 

 was poured on the ground were then lifted and all the aphides were 

 found dead. All the other hills covered by bowls showed all the lice 

 dead and not all the bisulphide evaporated. The hills first treated 

 were again examined and there was no sign of recovered life anywhere 



