=The Cold Dip.=—For the dip, the tub is filled with water at a temperature of from 65° to 55° F. The duration of the dip varies from two or four seconds to one or two minutes. The bather should wet the face and chest before entering the water. It is best to enter the bath suddenly, as the sensation of cold is thus far less noticeable than when the bath is entered gradually. If the stay in the tub is more than momentary, vigorous rubbing must be kept up during the entire time spent in the tub. For persons in good health a cold dip on rising in the morning is excellent. It creates an appetite, accelerates the circulation, arouses the nervous system, and produces decided exhilarating effects in those who are strong enough to react after it. When employed for this purpose, the immersion should not be more than from three to fifteen seconds. The bather must rub herself vigorously while in the tub, and follow the bath with brisk toweling and plenty of friction. She should then take moderately active exercise for fifteen to twenty minutes. For any one just beginning to take the cold dips, the temperature of the water should be just 1 degree below that of the body, and gradually lowered by a drop of 1 degree every morning or two. Or, the dip may be preceded by a preliminary warm bath or warm shower. The salient point in connection with bathing is not to allow the skin to lose heat too rapidly. To apply this as a warning in the case of cold baths: it has been estimated that the heat loss from the body immersed in cold water at the temperature of 86° F. is double the normal; at 77° F., three times, and at 68° F., five times, the normal. The daily use of the cold dip for those who are able to react after it is one of the best means of fortifying the system against both acute and chronic diseases. _Contraindications._—The use of the cold dip is contraindicated for young children, the aged, and in run-down conditions of the system; in all cases where the action of the heart is weak, in Bright’s disease, or in any acute or chronic congestion of the kidneys; in all acute inflammations, as inflammation of the bowels, peritonitis, or inflammation of the uterus and ovaries. =Alkaline Baths.=—For these baths from 4 to 12 ounces of the carbonate of soda should be used to 30 gallons of water. The water should have a temperature of from 92° to 96° F. This bath is useful in many forms of skin disease, and relieves the itching of jaundice and urticaria. =Saline Baths.=—The typical saline bath is the salt-water bath. Sea-water contains in solution from ⅓ to ¼ pound of solids to the gallon of water. The principal ingredients are common salt, magnesium chlorid, and magnesium sulphate. These substances have a decidedly stimulating effect upon the skin and encourage reaction. For an artificial sea-water bath, 8 pounds of sea-salt should be used to 30 gallons of water.