his doors and windows hermetically closed. During the noontide glare, when the youngsters of the native patricians run about in white muslin inexpressibles, and their plebeian comrades in a still less expressible and certainly unspeakably sensible costume, the children of the north have to mourn their exile in black broadcloth, woolen stockings, boots or air-tight gaiters, tight-fitting collars, neckties, and waistcoats, besides the unavoidable flannel undershirt. And, worse than that, the ex-hyperborean not only continues to gorge himself with an amount of calorific food that would more than suffice for the climatic exigencies of his own latitude, but persists in eating that excessive amount in the specially indigestible form of fried and broiled meat, served smoking hot with greasy sauces, after a prelude of sudorific doses of hot soups or narcotic drinks. In a cold climate the pathological results of overfeeding are chiefly limited to the evils of mal-nutrition, i. e., the difficulty of eliminating the cachectic elements of a mass of accumulated and fermenting ingesta. But in a warm climate that result is complicated by the further difficulty of maintaining the normal temperature of the system. For the organic functions of the animal body require a uniform degree of warmth as a condition of their healthy performance, and in the human body the normal average of that temperature has been found to be about 98° Fahr. A variation of only two degrees denotes an abnormal depression or acceleration of functional activity, a difference of five degrees indicates a serious disease. In the polar regions, where a rousing stove-fire often fails to thaw the rime-frost on the stove-pipe, the organism of the human body contrives to maintain its blood-heat within half a degree of the normal average, i. e., sometimes at a temperature of 150° above that of the external air. In the tropics the same marvelous organism becomes a refrigerating apparatus, and lowers its temperature as much as thirty degrees below that of the outer atmosphere, which in British India, for instance, has been seen at 132° above zero, or a hundred degrees above the freezing-point.
In these thermal regulations, Nature has, however, to rely on the co-operation of instinct or reason; and a mariner who would wear the same dress on a north-pole expedition and a trip to Suez could hardly hope to escape the consequences of his imprudence. But even if the Arctic explorer should not only forget his furs, but intentionally chill his blood by sitz-baths on an ice-floe, and promenades in the costume of the Nereids, his chances of continued health could hardly be worse than those of the British merchant who practices in the tropics the calorific artifices of his native land, and aggravates the blood-seething effects of a West Indian summer by superfluous clothes and worse than superfluous beefsteaks and sudorific drinks. The blood of the sitz-bathing mariner would congeal; the blood of the beef-eating merchant does ferment. With all diversity of opinion as to the proximate cause of climatic fevers, there is no doubt that the febrile blood-changes