Who can enumerate the expedients advised to extirpate these venomous pests! Snuff, tobacco water, soot, guano, lime, ashes, and the like have been essayed, and succeeded for the most part only when, their too acrid form destroyed the plants! The cu-eumksr flea-beatle. (Hottica pubescens,) a hopping little black demon, generally infests the plants on the maturing of the cotyledon. I have temporarily succeeded in debarring, the insects of this elans from their plunder, by placing, around the plants a cordon or circle of plaster of Paris well sprinkled with spirits of turpentine. The rapid evaporation of the turpentine, however, rendered its frequently required repetition too troublesome.

This annoyance induced me to profit by a hint, derived from the practice of Mrs. Loudon, who expelled the aphides of her rose trees by a strong decoction of quassia. I directed four gallons of boiling water to be poured on four pounds of quassia chips, contained in a barrel. After twelve hours digestion the barrel was filled with cold water. This preparation, freely administered through a watering-pot, although it did not kill the black flea beetles, rendered the leaves quite unpalatable and every plant escaped harm from their attempted depredations. The striped melon bug ( Galereuca vittatti) usually follows the beetle. The application of the quassia water to the plants was continued, at the close of the day; and it was gratifying to find in ft an immunity also from the assaults of the bugs of this kind. If the quassia water were omitted one or two days the return of these foes was injuriously manifest.

The most persisting enemy to the melon, devouring plants and fruit, is the squash or pumpkin bug, ( Corcus tristis.) As long as the vines were damp with the quassi water, the bugs of this class made but triffing encroachments; soon as they were dry, they were again busy, disregarding the bitterness so much modified by evaporation. I then directed that a pound of common gine should be solved m water, and added to ten gallons of a quassi preparation of double strength. This glutinous liquid adhered to the plant*, and molestation to both vines and fruit, thereafter ceased. The quassi water, in its strongest form, is perfectly harmless to nearly all vegetation, and especially of this tribe, which will allow the melon cultivator to increase its animal disturbing power to any degree consistent with economy. A plantation of Bermuda squashes was made on another part of the ground at some distance from the melons. The quassi water was not applied. The ravages of the pumpkin bugs were comparatively surprising.

Mr. Hope, the expert gardener of my neighbor, J. Tuckerman, Esq.. - had recourse also, to the quassi liquid, and attributes the injury and loss that occurred to some of his melons, to the omission of the same.

Another opponent to melon growers - the white grub or cut-worm - has never troubled me. Professor Mapes asserts, that salt, scattered around the plant, or incorporated with the soil, in the proportion of six bushels to the acre, will prove an effectual exterminator. Mr. Smith, of Newport, in a former No. of this Journal, advises the covering of the beds with charcoal powder, for a protector.