Fumigating is employed for the destruction of certain insects; the inhaled vapour or smoke arising from some substances being fatal to them. Tobacco (see Tobacco) is the usual substance employed; and it may be ignited, and the smoke impelled upon the insects by bellows; or the ignited tobacco may be placed under a box, or within a frame together with the affected plant. The vapour of turpentine is destructive to the scale and other insects, employed in this mode. Mr. Mills has also stated the following as the best mode of fumigating with tobacco.

" According to the size of the place to be fumigated, one or more pieces of least iron, one inch thick, and three inches over, are made red hot; (pieces of old tiles, such as are used for covering smoke flues, would probably answer equally well;) one of these is placed in a twenty-four sized pot, on which is put the quantity of tobacco considered necessary to charge the structure with smoke sufficient to destroy insect life. To fumigate an ordinary sized eight-light house, I use three heaters, and three twenty-four sized pots, which I have placed on the front flue or walk; one pound of strong tobacco is put on the three heaters in equal parts, and this I find sufficient to fill the house, so as to destroy all the kinds of insects that perish by fumigation. The system has these advantages: the tobacco is so quickly consumed, that the house is completely filled in a very short time, and but little smoke can escape before the insects are destroyed; the pure heat from the iron heaters prevents injury from gas, and as no blowing is required there is no dust: it being only necessary to put the tobacco on the heaters, and leave the house." - Gard. Chron.