All drinking of these medicinal waters for remedial effects should be solely under the di rection of a physician. The effects upon each individual are largely constitutional and a course of water beneficial to one may be highly injurious to another. As a general rule min eral water at the springs is taken before break fast, at intervals of about a quarter of an hour between each tumbler, moderate exercise being taken in the intervals. In many cases bathing is of even greater importance as a remedial agent than drinking. Baths are gen erally between breakfast and dinner, and should never he taken soon after a full meal. The time during which the patient should remain in the bath varies very much at different springs, and the directions of the local physician should be strictly attended to on this point. As a general rule the treatment should not he pro tracted beyond the space of six weeks or two months, hut on this point the patient must he solely guided by the physician resident at the springs. As regards temperature, if the waters are between 70° and 98° they are called tepid, while all exceeding the latter are classified as hot springs. The following examples give the degrees of temperature found in different ther Chapelle, Prussia, 131°; Carlsbad, Bohemia, 162 .
American Springs.— In the United States the Rock Spring was known at Saratoga, N. Y., among the Indians as early as 1767, and over 40 springs have since been discovered there. In 1830 springs were well and popularly known in West Virginia, and of these the Bath mineral spring, now known as the Berkeley Spring, was visited as early as 1777, while the White Sulphur Springs were used by the Indians in 1778. In these American springs, like those in Europe, the geologists agree that dissolved min eral substances are obtained from the rocks through which the water has flowed. The ma jority of waters contain carbonic acid which greatly increases their solvent powers in the presence of lime, magnesia and iron. If the waters are alkaline they may take up sub stances which are ordinarily rather insoluble, such as silica. There is, undoubtedly, more or less relation between hot springs and the geological structure of a region.
Alkaline Waters.— Simple alkaline acidu lous waters are composed of carbonic acid and bicarbonate of soda. The most important springs of this class are the thermal springs of Las Vegas, N. Mex., and the cold springs at Sharon, N. Y. These waters are useful in cer tain forms of indigestion, jaundice, gallstones, gravel, gout and chronic catarrh of the respira tory organs. Muriated alkaline acidulous waters, which differ from the preceding, con tain a considerable quantity of chloride of sodium. The most important springs of this kind are the thermal springs of Ems and the cold springs of Selters and Salzbrunn. They are useful in chronic catarrhal affections of the bronchial tubes, the stomach and intestines.
Alkaline saline waters contain sulphate and bi carbonate of soda, such as the warm springs of Carlsbad, serviceable to patients suffering from abdominal plethora, if unconnected with dis eases of the heart or lungs. These waters afford an excellent remedy for habitual con stipation.
Bitter Waters.— The chief contents of these waters are the sulphates of magnesia and soda. The best-known springs of this class are those of Sedlitz and Kissingen; English examples are in the hitter waters of Cherry Rock, in Glou cestershire, and the Purton Spa, in Wiltshire, and in America the springs at Mount Clemens, Mich. These waters act as purgatives and diuretics.
Muriated Waters.— Simple muriated waters contain a moderate quantity of chloride of so dium or common salt. The chief springs of this class are Wiesbaden and Baden-Baden, which are hot; and those of Kissingen, Hom burg and Cheltenham, which are cold. The muriated saline springs of Saratoga, in the United States, are some of them chalybeate, others sulphurous or iadmous; all of them be ing rich in carbonic acid gas. The Ballston saline springs near Saratoga have a very high proportion of carbonic acid. They are chiefly emplayed in cases of gout, rheumatism and scrofula. Muriated lithia waters contain chlorides of sodium and lithium. In gout they first aggravate the pain, but then give relief ; and in periodic headache they have been found serviceable.
Earthy Watera.—These contain sulphate and carbonate of lime. The Wildungen water is a diuretic, and not only promotes the elimination of gravel, but by its tonic action on the mucous membrane of the urinary passages serves to prevent the formation of fresh concretions. It is also much used for chronic catarrh of the bladder. The baths of Leuk, in which many patients remain nine hours daily, until an erup tion appears, are chiefly used in chronic skin diseases.
Mild Thermal Waters contain a small amount of saline constituents. Of the springs of this class the most important are Hot Springs, Ark., and Roanoke, Va. Their most striking effects are to stimulate the skin and excite the nervous system. They are especially used in chronic rheumatism and chronic gout and in diseases of the skin.
Chalybeate Simple acidulous cha lybeates contain carbonic acid and bicarbonate of protoxide of iron. Saline acidulous chaly beates contain sulphate of soda and bicarbonate of protoxide of iron. The quantity of iron present is very small — from .08 to .15 in 1,000 parts. Many of the chalybeate springs, espe cially in Germany, contain also much carbonic acid; carbonate, sulphate and chloride of sodium are frequently present and may help in the cure. The Putnam Spring at Saratoga -and the springs of Maine and Massachusetts are ex amples of chalybeate wells which are very sel dom thermal. Maine has both chalybeate and sulphurous springs. Chalybeate waters are valuable in anemia.