under every parallel of latitude through which he passes from one temperate zone to the other. In warm and humid situations, such as Guayaquil, surrounded by rivers, stagnant pools, lagoons, and exuberant vegetation, atmospherical heat may operate in causing disease, not merely by promoting the production of miasmata, but also by increasing the irritability of the organs of the body, so as to predispose to severe attacks of illness. The affection of the skin commonly known under the name of “prickly heat” is very likely to arise from profuse perspiration while in Guayaquil; and all excess in the cuticular secretion should be avoided by every proper means, such as suitable clothing, temperate living, and moderate bodily exertion, &c. The contrary practice, of encouraging sweat by heating drinks, has a bad tendency, both moral and physical:—physically, it produces, sooner or later, gastric and hepatic diseases;—morally, it furnishes a pretext and excuse for deep potations;—and the end of all is a broken down constitution, and a mind impaired in its noblest powers. In another point of view, without supposing that the fevers which on the shores of the Pacific are termed putrid arise from the want of a due quantity of saline ingredients in the blood, it is not improbable that, when perspiration is excessive and too long continued, it may indeed carry off from the circulation more of these saline portions than can be quite compatible with a state of perfect health. We have sometimes observed horses, when hard pressed on a hot day along the sandy plains of Peru, lie down exhausted and overcome by excessive sweat and muscular exertion; and, on being unsaddled and allowed to cool, the poor animals on such occasions would appear as if covered with hoar-frost, from the quantity of saline matter left behind from the fluids perspired and evaporated. Moderate transpiration, however, is a cooling process, and a necessary one to the natural condition of the system, when the circulation of the blood is much increased, as is the case under high atmospherical temperature, though at the same time muscular vigour usually becomes much diminished under such circumstances. The functions of the stomach often grow languid as the relaxation of the skin has been great and long continued; but, while the appetite is thus diminished, the flow of bile is apt to be increased, and the bowels often become irregular,—sometimes too lax and irritable, at other times torpid and costive.