Manganous Chlo′′ride. MnCl2. Syn. Protochloride of manganese, Muriate of m.; Manganesii chloridum, L. Prep. 1. By saturating hydrochloric acid with manganous carbonate; the solution is greatly concentrated by evaporation, when crystals may be obtained, or it is at once evaporated to dryness; in either case the product must be placed in warm, dry, stoppered bottles, and preserved from the air.
2. From the dark brown residual liquid of the process of obtaining chlorine from binoxide of manganese and hydrochloric acid; this liquid is evaporated to dryness, and then slowly heated to dull redness in an earthen vessel, with constant stirring, and kept at that temperature for a short time; the greyish-looking powder thus obtained is treated with water, and the solution separated from the ferric oxide and other insoluble matter by filtration; if any iron still remains, a little manganous carbonate is added, and the whole boiled for a few minutes; the filtered solution is then treated as before. This is the least expensive and most convenient source of this salt.
Prop., &c. Rose-coloured tabular crystals; inodorous; very soluble both in water and alcohol; very deliquescent; when gradually heated to fusion the whole of the water is expelled, and at a red heat it slowly suffers
decomposition. Astringent, tonic, hæmatinic, and alterative.—Dose, 3 to 10 gr.; in scorbutic, syphilitic, and certain chronic cutaneous affections; anæmia, chlorosis, &c.
Manganous Hydrate. Mn(HO)2. Syn. Hydrated protoxide of manganese. Prep. Formed by adding potassium hydrate to manganous sulphate, and filtering and drying the precipitate in vacuo. White powder rapidly absorbing oxygen and burning first green and then brown from formation of higher oxides.
Manganous I′odide. MnI2. Syn. Manganesii iodidum, L. Prep. By dissolving the carbonate in hydriodic acid and evaporating the filtered liquid in vacuo or out of contact with air.—Dose, 1 to 3 gr.; in anæmia, chlorosis, &c., occurring in scrofulous subjects.
Manganous Oxide. MnO. Syn. Protoxide of Manganese. Prep. By passing a current of hydrogen over manganous carbonate heated to whiteness in a porcelain tube. Olive-green powder rapidly oxidising on exposure to air, and soluble in acids forming manganous salts.
There are four other oxides and two oxyhydrates that may be treated of here, but of which only the peroxide and the manganates and permanganates are of practical importance.
Manganous-manganic Oxide. Mn3O4, or MnO.Mn2O3. Syn. Red oxide of manganese, Protosesquioxide of manganese. Found native as “Hansmanite”. It is produced by igniting manganous carbonate, or manganic oxide, or manganic peroxide. Reddish-brown, coloured crystals or powder, and communicates an amethyst colour to glass when fused with it.
Manganous-manganic Peroxide. Mn4O7 or MnO3.Mn2O3. Syn. Intermediate, oxide of manganese. Found native as “Varvicile,” as a black hard crystalline mass. Decomposed when heated into a lower oxide and oxygen.