6. French Gardening, as s Science, and as to the Authors it has produced
293. The science of gardening is well understood in France among the eminent gardeners and professors; perhaps better than in any other country. Quintinye and Du Hamel applied all the physiological knowledge of their day to the treatment of fruit and forest trees; and the theories of grafting, of healing wounds, and of artificial excitements to fruitfulness, were explained in their works. Rozier, Aubert du Petit Thouars, Bosc, and above all Professor Thouin, have brought the sciences of chemistry and of botany to bear on the various parts of gardening and rural economy, which they have treated of in various works, but especially in the Nouveau Cours d' Agriculture (14 vols. 8vo), published in 1810. The art of heating hothouses by hot water was invented in France by a physician of the name of Bonnemain, in 1777, and the hothouses in the Jardin des Plantes, were heated in that manner in the time of Louis XVI., though it was afterwards given up, in consequence of the first revolution. Herbaceous grafting was first invented and extensively practised by the Baron de Tschoudy, in the neighbourhood of Metz. (Ann. de l' Agr. Franc., tom. xxix.) Dutrochet, well known to the scientific world, as connected with anatomical and physiological researches, has made extensive discoveries in physiological botany, and illustrated the laws of vital motion in plants. (Agent immediat du Mouvement Vital, &c.; and Gard. Mag., vol. iii. p. 78.) The supposed influence of the moon on plants is shown by M. Arago to be founded on fact; and he explains its effects on the principles established by Dr. Wells in his Treatise on Dew. In clear moonlight nights, the uninterrupted radiation from the earth's surface does injury by the cold it produces; while cloudy nights, or those without moonshine, prevent radiation, and keep plants on the surface of the ground warm. (Gard. Mag., vol. iii. p. 464.)
