From a little plane covered with grass, distant from the rivulet three yards, and four from the ash-coloured trachytic rock, water bubbles up at various points, forming large globules, as if boiling. Its temperature is 94° of Fahrenheit, that of the air being 68°. In the corner where these jets are found, there are at short distances small wells of equal temperature, except one at 67°, which is found at the distance of a yard from the principal jet; and it is the more worthy of notice, as it happens to be very near to the water which indicates higher temperature. All these little wells render tribute to the principal one, and to the rivulet; their banks, and the bottom of one of the baths, contain a very fine yellow substance, which is the true oxide of iron. These waters are very transparent, without smell, and with taste half acidulated and astringent; they disengage a gas which, passed through lime-water, or a solution of the acetate of lead, throws down precipitates soluble with effervescence in acetic acid. They redden the tincture of violets and blue paper, which loses its colour on drying, and this proves the existence of a free acid; being agitated, an air is disengaged with noise: all the acids, weak and strong, produce effervescence with these waters. The prussiate of potash, when a little of any acid is added to it, causes in the ferruginous water a blue precipitate, which is the prussiate of iron. Iron-water being boiled, it loses the property of effervescing with the acids, of forming a precipitate with the prussiate of potash, and also its astringency. A bottle of water being evaporated affords, during the operation, a light, white precipitate, and its surface becomes covered with a most delicate film. The operation, if continued to dryness, yields sixteen grains of salts, which I have analyzed. It appeared from the analysis that the iron-water is composed of the following ingredients and proportions. One bottle, or a pound and a half, of water afforded Carbonic acid 10½ grains. Muriatic acid 2 Sulphuric acid ¼ A hundred grains of the salts were composed of Carbonate of magnesia 26 grains. Carbonate of lime 6 Muriate of soda 15 Bicarbonate of soda 40 Sulphate of iron 3 Insoluble matter, consisting of silex and sulphate of lime 8 --- 98 --- This water greatly resembles, in its contents, that of Selz, Spa, and Carlsbad. The exact quantity of carbonic acid which it disengages could not be ascertained, for want of proper instruments for the purpose. The carbonic acid of the saline parts is sufficient to saturate the lime, magnesia, and soda. MEDICINAL VIRTUES OF THE FERRUGINOUS WATER OF YURA.