As it is the combination of heat and moisture that renders the thermal bath so efficacious, it frequently happens that a thoroughly hot bath most effectually facilitates the cure, and we are not astonished that the parboiling waters of Emmaus, at 148 deg., on the shores of Tiberias, are as famous for their cures as any of the German baths. The semi-barbarians about the sea of Galilee, the inhabitants of Iceland, and the savages of America, know how to employ the hot bath skillfully; and if we were equally accustomed with them to exercise our natural instinct and common sense, we also might bathe in hot water without consulting the doctor; but as it is, we had better take advantage of a better opinion than our own. I the more earnestly urge this course, because I know the danger of all hot baths, wherever there is acute disease of an inflammatory kind affecting internal organs, more especially of the lungs, heart, and bowels. Even _acute_ rheumatism is more likely to attack the heart when the hot bath is employed; and where there is any considerable structural disorder of that organ, the use of the bath in any form is at all times attended with risk. Warm baths are useful in all nervous disorders attended with debility, in all cases in which there is dryness of the skin and a tendency to feverish less, in mental fidgetiness, in irregular circulation, as when a person can not take due exercise, and is subject to coldness of the feet or hands, and in many forms of congestion and dyspepsia, with tenderness over the stomach. It is serviceable in the convulsive diseases of children, and in painful diseases, especially of a spasmodic kind, but more particularly in cases of chronic irritation from local causes, whether of the skin or of internal parts. It is injurious to plethoric persons, to persons subject to haemorrhage of any kind, and in the active stage of fever. But whether it would be good or bad in any individual case, can be determined only by one who has ability to examine and judge of that case. As a general rule, mineral and salt-water warm baths are less relaxing than those of pure water. The vapor bath, when the vapor is not breathed, acts more powerfully, though much in the same manner as the warm bath, but it is more useful in common cold and rheumatism. The warm-air bath, at from 100 deg. to 120 deg., is highly convenient and useful, where it is desirable to excite perspiration, as in rheumatism, scaly eruptions, and certain stages of fever and cholera. The plan most readily adopted is that of Dr. Gower: A lamp is placed under the end of a metallic tube, which is introduced under the bed-clothes, which are raised from the body by a wicker frame-work, and the degree of heat regulated by moving the lamp.