By protecting the skin from the air, we concentrate on it the heat that is ever exhaling from the body, and thus complete what warm baths, spirituous liquors, want of exercise, close rooms, and heavy nourishment, have begun. We do not perceive that by keeping the body warm, we weaken the skin, which becomes so sensitive to external changes, that we are incessantly obliged to augment the thickness and number of its coverings. At last, a time comes when nothing more can be added to the clothing already too heavy. Then weak and irritable persons, whose numbers--our erroneous system daily augments!--remain at home, not aware of the innumerable inconveniences to which such a resolution exposes them, and not knowing that the habitual washing of the body in cold water, would enable them to leave their heated apartments, abandon flannel, and expose themselves, without the slightest danger, to the healthy effects of fresh air. It is the enervating softness and delicacy of modern customs, which present the greatest obstacle to the use of cold water. Man looks for agreeable impressions, and avoids whatever does not produce them. But with a little courage, he would discover that the inconvenience of a more rigorous and simple mode of life was but momentary, and when he had found his health of mind and body improved by it, it would soon become agreeable, whilst from luxurious sloth ensue enervation and disgust. Being unable to change the nature of the elements, we should harden our bodies, familiarise ourselves with the inclemency of the seasons, and turn them to the benefit of our health. It is in vain that the man whose fortune permits him to change the climate, looks for a milder sky; if his effeminacy accompanies him, he will be like a lady of whom Priessnitz speaks, who near the fire was cold. A warmer air would enervate his skin more and more; and then he would be as sensitive to cold, even in a Neapolitan climate, as, with a hardened body, he would be at his ease in the hut of an Esquimaux. Another obstacle to the external use of cold water, is the false belief that colds, which are the sources of much illness, result from it. People cannot understand that a cold bath, followed by suitable exercise, warms the feet and the body, and that there is _no_ surer preservative from cold. The same incredulity is affected with regard to the revulsive effect of the cold foot-bath; nevertheless nothing is better proved than its efficiency in relieving the head. Every one knows that, after having washed the face and hands in cold water, an agreeable warmth ensues, which is not the result of warm water. That after any part of the body has been exposed to cold, rain, or snow, it becomes hot; and that the reverse is the case after the use of warm water; which accounts for people in Summer feeling cool after a warm bath.