But to return to the kitchen-gardens. Pretty as they are to the eye, they are not considered to be wholesome; and no Roman will live in a house near one of them, especially if it lie on the southern and western side, so that the Sirocco and the prevalent summer winds blow over it. The daily irrigation, in itself, would be sufficient to frighten all Italians away; for they have a deadly fear of all effluvia arising from decomposing vegetable substances, and suppose, with a good deal of truth, that, wherever there is water on the earth, there is decomposition. But this is not the only reason; for the same prejudice exists in regard to all kinds of gardens, whether irrigated or not,--and even to groves of trees and clusters of bushes, or vegetation of any kind, around a house. This is the real reason why, even in their country villas, their trees are almost always planted at a distance from the house, so as to expose it to the sun and to give it a free ventilation; these they do not care for; damp is their determined foe, and therefore they will not purchase the luxury of shade from trees at the risk of the damp it is supposed to engender. On the north, however, gardens are not thought to be so prejudicial as on the south and west,--as the cold, dry winds come from the former direction. The malaria, as we call it, though the term is unknown to Romans, is never so dangerous as after a slight rain, just sufficient to wet the surface of the earth without deeply penetrating it; for decomposition is then stimulated, and the miasma arising from the Campagna is blown abroad. So long as the earth is dry, there is no danger of fever, except at morning and nightfall, and then simply because of the heavy dews which the porous and baked earth then inhales and expires. After the autumn has given a thorough, drenching rain, Rome is healthy and free from fever.