The temperature of the former rarely exceeds 72° F. while that of the latter is generally about 55° F. Of the warm acidulous waters are those of Mont-D'or, Saint Nectaire, Clermont-Ferrand, in the department of Puy-de-Dôme; Vichy, Bourbon-l'Archambault, dep. l'Allier; Audinac, Ussat, dep. l'Arriège; Chateauneuf, Saint-Mart, Chatel-guion, dep. Puy-de-Dôme; Dax, dep. Landes; Saint Alban on the left of the river Loire.
Of the cold acidulous waters there is Pougues in the department of Nièvre; Chateldon, Bar, Saint-Myon, Médague, Vic-le-Comte, dep. Puy-de-Dôme; Mont-Brison, Saint-Galmier, dep. Loire; Langeac, dep. Haute-Loire. They are tonic and diuretic; and in large doses produce a sensible degree of exhilaration.
They all afford a grateful and moderate stimulus to the stomach, but the warm acidulous springs are to be preferred as there are few of this kind that do not contain a small portion of Iron and a larger portion of carbonic acid gas, and are especially useful in all cases of impaired digestion; while those which contain alkaline carbonates, as Pougues and Saint-Galmier, are more particularly employed as palliatives in calculous affections.
Chalybeate. Waters thus named owe their properties to iron in combination generally with carbonic acid; and as the latter is usually in excess, they are often acidulous as well as chalybeate. The metal is found also in the form of a sulphate, but the instances of this are very rare.
Chalybeate waters have a styptic or inky taste: they are, when fresh drawn, transparent, but become black when mixed with tincture of nut-galls; but an ochery sediment soon falls, and the water loses its taste. If the iron be in the state of sulphate, however, no sediment falls; and the black colour is produced by the above test, even after the water has been boiled and filtered. Chalybeate springs are very numerous in France, some of the following are much frequented: Rennes-Les-bains, in the department of l'Aude; Saint-Honoré, Passy, near Paris; Forges, Aumale, Rouen, dep. Seine-inférieure; Contrexeville, dep. Vosges; Bussang, Provins, dep. Seine-et-Marne; La Chapelle-Godefroi, dep. of l'Aube; Saint-Gondon, Noyers, dep. Loiret; Fontenelle, dep. Vendée; Watweiler, Upper-Rhine; Cransac, dep. l'Aveyron; Sainte-Marie, dep. Cantal; Sermaise, dep. Marne; Ferrières, Segray, dep. Loiret; Alais, dep. Gard; Boulogne-sur-Mer, dep. Pas-de-Calais; Vals, dep. l'Ardèche.
Chalybeate waters are powerful tonics, and are employed in dyspepsia, scrofulous affections, cancer, amenorrhœa, chlorosis, and other diseases of debility for which the artificial preparations of iron are used. Much of the benefit derived from the use of chalybeate waters depends on the extreme division of the metalic salts they contain, as well as the vehicle in which it is held in solution; while at the same time their operation is much modified by the carbonic acid gas by which the iron is suspended. When the water is a carbonated chalybeate, it should be drunk the moment it is drawn from the spring; but the same precaution is not necessary with a water containing sulphate of iron.
Sulphureous. Waters classed under this head derive their character chiefly from sulphureted hydrogen gas; which in some of them is uncombined, while in others it is united with lime or an alkali. They are transparent when newly drawn from the spring, and have a fœtid odour which is gradually lost from exposure to the air, and the water becomes turbid. When they are strongly impregnated with the gas, they redden infusion of litmus, and exhibit some other of the characteristics of acids; and, even in a weak state, they blacken silver and lead.
Besides containing sulphureted hydrogen gas, they are not unfrequently, also, impregnated with carbonic acid. They generally contain muriate of Magnesia or other saline matters, which modify their powers as a remedy.
The warm sulphureous springs in France are those of Barèges, Saint-Sauveur, dep. Upper Pyrénées; Cauterets, Bonnes, Cambo, dep. Lower Pyrénées; Bagnères-de-Luchon, dep. Haute-Garonne; Ax, dep. l'Arriège; Gréoult, Digne, dep. Lower Alpes; Castera-Verduzan, dep. Gers; Bagnols, dep. Lozère; Évaux, dep. Creuse; Saint-Amand, dep. Nord; Loèche, right of the Rhône; Aix-la-Chapelle. The cold sulphureous waters are those of Enghien-les-Bains, in the department of Seine-et-Oise; La Roche-Posay, dep. Vienne; Uriage, near Grenoble.
These waters are resorted to chiefly by patients who labour under cutaneous affections and are applied locally as well as drunk.