One of the most curious, and at the same time impressive, of the phenomena of the bath, is the relative freedom of perspiration of the educated and the uneducated skin; in other words, of the practised and the unpractised bather. There are certain persons who have never perspired, and these persons require a long training in lower temperatures before they can be admitted with safety to the higher temperatures; they are also much assisted by the addition of watery vapour to the hot air, converting it, in fact, into a vapour-bath. But of the rest of mankind, who present every facility for active perspiration, but who have never had, or but seldom have, the skin aroused to its normal activity, the variety in the energy of perspiration is very remarkable. The practised bather is enveloped in a sheet of perspiration, while the skin of the beginner is hardly moist; if the practised bather but raise his arm, the water drips from his elbows and finger-ends in continuous drops; his cummerbund is saturated, and the water may be wrung from it as from a soddened cloth, while the cummerbund of the neophyte is still dry. If the beginner rest his back for an instant against the wall of the Calidarium, he shrinks away from it, because of the intensity of its heat; but the practised bather presses against it with all his force, and receives only the sensation of an agreeable warmth, because the abundant moisture of his skin is sufficient to keep the wall cool. The beginner loses the moisture only of the surface of the body, and feels no resulting internal sensation; but, in the practised bather, the skin sucks up the watery fluids from the deeper streams of the sanguine flood, and the bather thirsts in the operation. He drinks water from time to time to replenish the waste; pint upon pint is taken into his stomach, and finds its way firstly into the blood, and then into the sudatory system of the skin; surely an apparatus of organs and a current of blood so rinsed by the transit of pure water must undergo an important purification. To the practised bather the drinking of water during the perspiration of the body is reviving and necessary, because his blood has need of water to supply the place of that which has been withdrawn by the skin, and the amount of need is expressed by his thirst. But the beginner has no thirst, and he will do well to avoid drinking, as calculated to increase the labour of perspiration, and likely therefore to be followed by oppression and faintness.