Another active agent in the production of disease in these climates is the great fall of dew which takes place between the setting and rising of the sun, and the extreme degree of cold which attends it. The dew begins to fall as soon as the sun gets below the horizon, and increases till about an hour or two before dawn; the cold at that time is extreme, more particularly felt on account of the great heat which is experienced during the day. The cold is the immediate cause of the falling of the dew, which is only the water that was dissipated in vapour by the action of the sun’s rays. The dew favours the action of the cold; and persons who are exposed to it, are in consequence frequently attacked with disease. Persons unaccustomed to the heat, and ignorant or regardless of the consequences of exposure to the night air, often suffer much, and become affected with the peculiar distempers of the climate, in this manner: they lie down on the ground scantily covered, while the sun is still above the horizon, and make no provision for the cold and damp of night which is sure to overtake them. Persons go to bed also with too few clothes, being then warm and oppressed with heat; in the night the dew falls, the cold arrives, and they are often awakened with severe rigors or shiverings; and thus fever, dysentery, and the like disorders are induced. The winds in all latitudes are often instrumental in the production of disease. Some have been already referred to in connexion with the conveyance of vitiated air. Some are hurtful from their excessive heat, as, for instance, those blowing directly off the burning deserts of Arabia and of Africa. The Sirocco is not only extremely hot, but is copiously loaded with aqueous vapour. It visits Italy, blowing there several days at a time, and acts almost as a vapour bath upon the inhabitants. The Sirocco blows off the deserts of Africa, passing over the Mediterranean sea, there imbibing a large quantity of water, converted into vapour, and rushes upon the fair shores and degenerate population of Italy. Its immediate effect is to relax the system, and to open up all the pores on the surface of the body. These effects are very hurtful to health, and become particularly so, when they are long continued, as sometimes happens. But more dreadful are the results of exposure of persons so situated, to the sudden action of an intensely cold blast, such as the Tramontane, which, driving from the northern side of the Alps and Pyrenees, passing over their snow-capt summits, and sharing their bitterness and frost, rushes, without warning, upon the inhabitants. The tramontane is very cold, and acting upon persons in a manner “forcing” in a hot house, soon produces pleurisies, colds, consumptions, &c. &c.