“In the month of June I selected about twenty large Pine plants, some of which had green fruit on them, and their leaves, fruit, and roots, were almost covered with insects. These plants I plunged in a tan bed, with a very gentle heat in it. The tan bed was in a brick frame designed for rearing succession plants: it was nearly five feet wide, twenty feet long, and the glass frames were close and in good repair. These plants I watered frequently and plentifully, sometimes twice a day, with water not less than 70 or 80 degrees, and sometimes 100, warm: in short, I kept the plants constantly in a moist air, by plentiful waterings without measure; and, excepting the time of giving water, I kept the lights constantly close shut down, even in the hottest sunshine, without shading the plants. In this frame I had no thermometer, but the heat was, I think, sometimes about two or three o’clock in the afternoon, upwards of 120 degrees. This great heat and much moisture caused the plants to grow most vigorously; and having subjected them to the said mode of management for a few weeks, the insects, in the course of that time, were totally destroyed, many of them lying dead on the leaves and fruit. In the spring-time, before this operation, the plants had been strewed with sulphur, which, at least, is a harmless dressing to plants of any kind, and probably may be of use in preventing insects from breeding numerously, or the means of depriving them of part of their natural food. This circumstance, however, I just here mention, because, from experiments which I have tried since then, it is probable that the effluvia arising from flour of sulphur, being scattered on the leaves, or about in the hot-house, in conjunction with heated air and moisture, may more suddenly destroy insects than heat and moisture alone; but it ought to be remembered, that if sulphur be by any means set on fire in a confined place, among plants of any kind, it will either totally destroy or greatly injure them.