known as the Berkeley Spring, was visited as early as 1777, while the White Sulphur Springs were utilized in 1778. The therapeutic action of mineral waters or spas, as they are frequently termed, depends largely on their chemical composition and their temperature, although a variety of other circumstances, such as situation, elevation, climate, mean temperature, and above all the regular habits of the patient, have no doubt an important bearing on the success of the treatment.
Origin. The origin of mineral waters is often looked upon with much curiosity, and yet there is nothing unnatural about it. The rain water falling on the surface soaks down through the soil into the rocks and may slowly filter through them to a considerable depth, coming out to the surface at a lower level in the form of a spring; or again the water may reach sufficient depths to be subjected to great pressure or even heat, and coming to a fissure or being struck by an artesian-well boring, it will tend to escape to the surface through such an outlet. Many mineral springs are found along lines of faulting, since fault fissures afford a means of escape. The dissolved mineral substances no doubt are obtained from the rocks through which the water has flowed. In some cases the waters in seeping through one type of rock may take up certain acids which later react on basic elements contained in other rocks, thus producing salts. Most waters contain some carbonic acid, which greatly increases their solvent powers in the presence of lime, magnesia, and iron; while if the waters are alkaline they may take up substances which are ordinarily rather insoluble, such as silica. The attacking power of the water may be still further increased if it is hot. There seems to be some relation between hot springs and the geological structure of a region, as thermal springs are more abundant in areas where the rocks have been highly faulted or where there has been volcanic activity in comparatively recent geological times. Mineral springs commonly contain more dissolved material in regions of sedimentary rock formation than in igneous or metamorphic areas.
Temperature. Springs are commonly characterized as thermal when they have a temperature of over 70° F. If the temperature is between 70° and 98° they are called tepid, while all exceeding the latter limit are included under hot springs. The following examples will serve to show the degrees of temperature found in different thermal springs: Sweet Springs. W. Va., 74° F.; Warm Springs, French Broad River, Tenn., 95°; Washita, Ark., 140° to 156°; San Bernardino Hot Springs, Cal., 108° to 172°; Las Vegas, N. M., 110° to 140°; Sulphur Springs, Aix-les-Bains, France, 108°; Kaiserquelle, Aix-la-Chapelle, Prussia, 131°; Karlsbad (Sprudel), Bohemia, 162°.
Flow of Springs. The amount of water which a mineral spring may discharge is quite variable; thus 500 springs in Central France, which were tested, yielded 2,628,000 gallons in twenty-four hours, and the famous Orange Spring in Florida is said to discharge 5,000,000 gallons per hour. The discharge per hour of some of the principal American springs is as follows: Champion Springs, Saratoga, 2500 gallons; Roanoke Red Sulphur Springs, Va., 1278 gallons; Warm Sulphur Springs, Bath. Va., 350,000 gallons; Hot Springs, Ark., 20,100 gallons; Glen Springs, Waukesha, Wis., 45,000 gallons; Horeb, Waukesha, Wis., 1500 gallons.
Classification. A classification of mineral waters may be geographic, geologic, therapeutic, or chemical. The following scheme of classification is one adopted by A. C. Peale, a noted authority on the subject of mineral waters, and more especially those of the United States:
CLASSIFICATION OF MINERAL WATERS.
| Alkaline | ||||
| Alkaline-saline | Sulphated | |||
| Muriated | ||||
| Saline | Sulphated | |||
| Muriated | ||||
| Acid | Sulphated | |||
| Muriated |
| |||
| Siliceous | ||||
Springs included in the above groups may be either thermal or non-thermal, and they may be either free from gas or contain carbonic acid gas (carbonated springs), sulphureted hydrogen (sulphureted), nitrogen gas (azotized), and carbureted hydrogen (carbureted). The alkaline waters include all those containing alkaline carbonates, such as carbonates of alkalies, alkaline earths, alkaline metals, or iron. About one-half of the alkaline springs of the United States are calcic alkaline, that is, containing calcium carbonates or bicarbonates as the predominant ingredient. The water of the Hot Springs of Virginia is a hot, carbonated, calcic alkaline water. The alkaline-saline waters include those containing combinations of alkaline carbonates with sulphides (sulphated) or chlorides (muriated), there being in the United States one-third as many as of the saline waters. In the saline waters sulphides and chlorides predominate; in the United States there are about one-third more springs of this class than of the alkaline springs. Springs which are classified as purgative or aperient will fall in the subclass of sulphated salines. The salines may be sodic sulphated or muriated, or calcic sulphated or muriated; the sodic muriated constitute about 88 per cent. of the muriated saline waters of the United States. The acid class includes all waters containing free acid, whether silicic, sulphuric, or hydrochloric. In addition to having free acid a spring may also contain salts of the acid.
Geographical Distribution. There are at the present time between eight and ten thousand mineral springs in the United States, and of this number 659 were listed as commercial producers in 1901. Most of the mineral springs of commercial value are found in the Eastern United States and in the Mississippi Valley; west of the 101st meridian they are largely confined to the Pacific Coast. No hot springs are known in the New England States. In Maine the springs are slightly alkaline-saline and chalybeated, with a few of carbonic character. Their temperature ranges from 40° to 46° F. Chalybeated springs are abundant in Massachusetts. Many of the springs of the New England States are utilized for commercial purposes, but among the Eastern States as a whole New York stands at the head of the list of producers. The springs at Saratoga have an international reputation, and compare favorably with any of the foreign spas, the waters from the Congress, Empire, Columbia, High Rock, Hathorn, and Geyser springs being extensively used throughout the United States.
