The phenomenon of vegetable life being destroyed by cold, probably arises from the vessels, through which the circulation and secretion of the fluids of plants take place, being ruptured by the expansion, from cold, of the fluid they contain. In proportion, therefore, to the tenuity of the vessels, and the abundance of their fluid, will be the danger to which they are exposed from frost; and to the strength of the vessels, and the paucity of their fluid, the power of resisting cold. Thus vigorous shoots of the oak, walnut, and many other trees, which are formed with rapidity, imperfectly matured, and highly charged with fluid, are extremely impatient of cold, and are even destroyed by a few degrees of frost; while the twigs and branches of the same trees, which are formed slowly, fully matured, and incompletely filled with fluid, bear unharmed the utmost rigour of our winters. In acclimatizing, therefore, this law should be carefully remembered, and the situations in which tender plants are stationed, should be those in which their growth is restrained, and an excessive absorption of fluid prevented. This appears to have been the true secret of the success that has attended the attempts at acclimatizing, which form the subject of Mr. Street’s communication. By planting in situations well drained from superfluous moisture, under circumstances where rapid growth was rendered impracticable, and, as we understand, in a garden admirably adapted to the object, from its position, he has succeeded in naturalizing, in latitude 56° N., plants which have not yet been known to endure the winters even of the parallel of London. V. _Upon the Culture of Celery_. By Thomas Andrew Knight, Esq., F.R.S., President. “That which can be very easily done, without the exertion of much skill or ingenuity, is,” Mr. Knight observes, “very rarely found to be well done, the excitement to excellence being in such cases necessarily very feeble.” This remark is in the present case applied to the cultivation of celery, which, being a native of the sides of wet ditches, might naturally be expected to demand an abundant supply of water when cultivated. Accordingly, Mr. Knight found that by keeping the ground, in which celery was planted, [p167] constantly wet, it grew by the middle of September to the height of five feet, and its quality was in proportion to its size. Mr. Knight also recommends planting at greater distances than is usually the case, and covering the beds, into which the young seedlings are first removed, with half-rotten dung, overspread to the depth of about two inches with mould; under which circumstances, whenever the plants are removed, the dung will adhere tenaciously to their roots, and it will not be necessary to deprive the plants of any part of their leaves.