Mineral Waters are those natural waters, usually obtained from springs, which have dissolved an appreciable quantity of salts and gases from the rocks and soil of their underground course. From the physiological point of view, mineral waters must contain a sufficient amount of inorganic salts, with or without dissolved gases, to enable them to exert a physiological effect.
Natural spring mineral waters derive their solid and gaseous components solely from their passage through soil and rocks, and not from artificially added substances; but it is sometimes necessary to treat them in order to remove excess iron, and to adjust the salt and carbon dioxide content to give the physiological effect desired. Waters which have been treated by adding salts and by charging with carbon dioxide are usually called artificial or imitation mineral waters.
The discovery of mineral waters, and their application for medicinal uses, probably occurred before the beginning of recorded history, for it is known that mineral waters were used for remedial purposes from the earliest days of Greece and Rome. About 400 B.C. the Greek physician Hippocrates wrote a book entitled Airs, Waters, and Places, in which the watering places of his time were described; and some 500 years later, in 77 A.D., Pliny wrote about the mineral springs in various parts of Europe. The Romans discovered the thermal springs of Italy, and as the empire expanded, they found many other celebrated European springs, including the hot sulphur springs of Aachen (Aix-la-Chapelle) and Baden-Baden, in West Germany; possibly at Spa, in Belgium; and those at Bath, in England. The sulphurous thermal springs at Tiberias in Lower Galilee have been used by invalids since Biblical times. Many well-known resorts—even cities—have been built around mineral springs; and some of these waters, including Seltzer and Vichy water, have achieved such worldwide renown that their names have been adopted for common use.
In the United States, Rock Spring at Saratoga, N.Y., among many other springs, was known to the Indians, and friendly Mohawks brought Sir William Johnson to bathe here in 1776. White Sulphur Springs, W.Va., was first used by white men in 1778. In the late 19th century, the spots for taking mineral water became very fashionable, with elaborate facilities set up to amuse the patrons, the waters usually being but an accessory to the social life. In general, American mineral springs have been much less extensively developed than those of Europe, and scientific research into the properties of these waters has been relatively neglected in the United States, although such research has had a definite place in European medicine. The State of New York, however, which purchased the spring area of Saratoga Springs and made it a state reservation, set up a research institute in balneology there in 1935. In 1921, Arkansas Hot Springs, believed by some to have been the "Fountain of Youth" which Ponce de Leon sought, was made a national park.
Among the first to produce mineral water artificially was the physician of the Elector of Brandenburgh, Leonhard Thurneisser, who prepared a sulphur water about 1572. In the United States the production of imitation mineral waters, made by the addition of salts or carbon dioxide gas to plain water, has become, along with the bottling of natural waters, a thriving industry.
The majority of the commercial springs of the United States are located in the older parts of the country east of the Mississippi. It has been estimated that there are about 8,800 mineral springs in the United States in about 2,700 separate areas, of which over 400 are used commercially. Wyoming, California, Virginia, Texas, Missouri, Colorado, and New York have the greatest number of springs. New York leads in the commercial exploitation of mineral waters. In the South, Kentucky, Tennessee, and Arkansas are the chief producers of mineral waters.
Among the best known United States waters are those of Saratoga Springs in New York State and several of the springs in Virginia and West Virginia. Among the better known European mineral springs are those of England, at Bath and Harrogate; the German springs at Baden-Baden, Bad Pyrmont, Aachen, Ems, and Wiesbaden ; the celebrated waters of Vichy and Dax in France; and those of Baden, Switzerland, and Carlsbad, Czechoslovakia.
The mineral waters at Gettysburg, Pa., and some at Saratoga, as well as those at Vichy and Ems, are generally cold and alkaline. Those of Nieder-Selters (Seltzer) and Bad Pyrmont, and the type known as Apollinaris, are carbonated. Alkaline-saline waters, also, are found at Saratoga. White Sulphur Springs and Salt Sulphur Springs, in Virginia, have sulphuretted waters, and Harrogate is a European spring of the same type. The geysers along Gardiner River and in Firehole Basin, in Yellowstone National Park, and the hot springs of Iceland are examples of siliceous mineral waters.
Although they sometimes have a greenish opalescent hue attributable to their content of various substances, mineral waters are generally clear. Occasionally they are whitish because of suspended calcium carbonate or free sulphur; some waters are slightly bluish because of suspended clay or slate; and others have a reddish tint due to a suspension of particles of red iron oxide or to the presence of reddish-colored algae.
Mineral waters containing hydrogen sulphide have the penetrating and unpleasant odor characteristic of this gas. A bitter taste in a mineral water is generally attributable to the presence of magnesium sulphate or sodium sulphate. Salty tastes are due to the presence of sodium chloride, and alkaline waters have a smooth feel and the characteristic brackish alkaline taste. Ferruginous waters have a definite styptic taste.
With respect to temperature at the source, mineral waters fall into four major groups: cold or nonthermal, with temperatures below 70° F.; tepid or thermal tepid, with temperatures between 70° and 98° F.; thermal, with temperatures from 98° to 107° F.; and hyperthermal, with temperatures above 107° F. Well-known examples of each of the groups include the cold springs of Sharon, N.Y.; the tepid springs at Warm Springs, Ga. (70° to 90°) and at Lebanon Springs, N.Y. (75°) ; the thermal springs of Hot Springs, Ark.; and the hyperthermal springs at San Bernardino, Calif. (108° to 172°), and at Steamboat Springs, Colo. (212°, with the water escaping as steam).
In addition to the mineral waters with the relatively common components discussed above, there are a number of special types of waters. Those containing the radioactive gas radon are known as radium waters; those containing lithium are known as lithiated waters; and other special waters contain strontium, arsenic, and iodine. These waters should never be used except by order of a physician.
With respect to their use, mineral waters may be classified into two principal groups: waters for table and for beverage use, and those for medicinal or therapeutic use. Medicinal waters include those taken internally as laxatives and for other purposes, and those administered externally. The use of mineral waters for therapeutic purposes is known as balneo-therapy.
With respect to their osmotic influence on the tissues of the body and the blood, waters for medicinal use which have an osmotic pressure less than that of the blood are called hypotonic; those which have an osmotic pressure equal to that of the blood are known as isotonic; while waters which have an osmotic pressure greater than that of the blood are called hypertonic.
The use of mineral waters for therapeutic purposes should be undertaken only upon the prescription of a physician, and then only for the specified length of time.
From the standpoint of gas content, mineral waters may be classified as carbonated, or containing carbon dioxide; sulphuretted, or containing hydrogen sulphide; nitrogen-bearing ; carburetted, or containing methane; oxygenated; and npngaseous. The first two groups are the most important.
Effervescent waters: In terms of carbon dioxide content, mineral waters fall into two groups: sparkling (effervescent) waters, which contain carbon dioxide; and npnsparkling (non-effervescent) waters, from which the gas is absent. When carbon dioxide escapes quickly from a mineral water, it is said to be free; and when it escapes slowly, it is said to be dissolved. In the former case, the carbon dioxide is under pressure when the water leaves the ground, and in the latter it is dissolved at a pressure only slightly above that of the atmosphere. The carbon dioxide may also be present as "half-bound," in the form of bicarbonate.
Sulphuretted-waters: The characteristic gaseous component of sulphuretted mineral waters is hydrogen sulphide which has an odor resembling that of rotten eggs. These waters (among the first to he known and used) were long esteemed for their curative powers. Some of the waters in Europe are those of Aachen; Baden, of metallic sulphides. The most important sulphur waters in Europe are those of Aachen; Baden, Austria; and Bareges, France. There are hundreds of such sulphur-bearing springs in the United States, including Richardson Springs, Calif., and White Sulphur Springs.
With respect to their chemical make-up, waters may be conveniently considered in terms of their principal constituents other than water itself: gases and salts.
With respect to type and concentration of salts, mineral waters are classed as saline, alkaline, alkaline-saline, alkaline-earth, ferruginous, and siliceous.
Saline: Saline mineral waters usually contain sodium ions for the most part, along with some potassium, magnesium, and calcium cations, and with chloride and sulphate anions; but at times iodide or bromide are present as well. When sodium chloride (common salt) is a principal ingredient, the water is sometimes termed muri-ated. Important springs with muriated waters are those at Wiesbaden and Baden-Baden. The so-called bitter waters, which act as purgatives, have as their principal components sodium chloride, magnesium sulphate (Epsom salts), and sodium sulphate (Glauber's salts). Well-known springs of this group include those of Bad Kissin-gen, Bavaria; Cherry Rock, in Gloucestershire, England; and Mount Clemens, Mich.
Alkaline: The alkaline mineral waters usually have sodium bicarbonate and sodium carbonate as their principal components, and sodium chloride and sodium sulphate are usually present also. Important springs of this class include the thermal springs of Las Vegas, N.Mex., and the cold springs of Sharon, N.Y.
Alkaline-saline: The mineral waters of the alkaline-saline group usually contain salts characteristic of each of the preceding groups. A typical alkaline-saline mineral water containing both sodium sulphate and sodium bicarbonate is that obtained from the warm springs of Carlsbad.
Alkaline-earth: Mineral waters of this group, also known as earthy waters, contain calcium sulphate and calcium carbonate, commonly termed sulphate and carbonate of lime. Such waters are found at Bad Wildungen, Germany, and at Leuk, Switzerland.
Ferruginous or chalybeate: Ferruginous waters contain ferrous iron as a component, normally in the form of the bicarbonate or sulphate; and usually sodium carbonate, sulphate, and chloride are also present. Two examples of ferruginous springs are at Chalybeate Springs, N.C., and at Chalybeate Springs, Ga. The majority of mineral springs in the New England region belong to the chalybeate group.
Siliceous: The siliceous mineral waters contain alkaline silicates as a principal component of the mixture of salts.