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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 pest 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 react them 
all, even with an underspray nozzle. A lot of pot grown plants be- 
coming badly in tested 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 G. Taylor, of Riverton, X. 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 drain v 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 the Coccinel- 
lidse were dead, the small lice dying, and the Diabrotiea, ants, and 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 un affected 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 lite anywhere 
