the boiling water; mix the two solutions, add the ammonia, stirring well (and boil for a short time); collect the precipitate on a calico filter, wash it with water until it ceases to precipitate a solution of nitrate of barium, and dry at a heat not exceeding 183° Fahr. The formulæ of Gregory and Dr Jephson are similar.
Ferrous sulphate, 8 oz., dissolved in a mixture of water, 10 fl. oz., and sulphuric acid, 6 fl. dr., is converted by means of nitric acid, 4 fl. dr., diluted with water, 2 fl. oz., into ferric sulphates; this solution is then added to another, formed by dissolving ferrous sulphate, 4 oz., in water, 1⁄2 pint; the whole is then mixed with liquor of potassium hydrate, 23⁄4 pints, and after being boiled for 5 minutes is collected on a calico filter, and washed, &c., as before; and is to be preserved in a well-stoppered bottle.
Prop., &c. The hydrate is a black sand-like substance, consisting of very minute crystals. When pure it is attracted by the magnet, and is entirely soluble in hydrochloric acid; and ammonia added to the solution throws down a black precipitate. The oxide is the chief product of the oxidation of iron at a high temperature in the air and in aqueous vapour. It is more permanent than ferrous oxide, but incapable of forming salts.—Dose, 5 to 20 gr. two or three times a day.
Ferroso-ferric Oxide. Fe3O4. Syn. Magnetic o. of i.; Ferri oxydum nigrum, F. o. magneticum (Ph. D.), Oxydum ferroso-ferricum, L. This occurs native, but that used in medicine is prepared artificially.
From the black scales of iron that fall around the smith’s anvil, by washing, drying, detaching them from impurities by means of a magnet, and then treating them by grinding and elutriation, as directed for prepared chalk. The product of this process is inferior as a medicine to the hydrate obtained as below, being less easily soluble in the juices of the stomach.
Ferroso-ferric Oxide. Fe3O4. Syn. Magnetic oxide. See Ferroso-ferric oxide.
Iron, Black Oxide of. (B. P.) Syn. Ferri oxydum magneticum; Ferri oxydum nigrum; Martial æthiops. Prep. Dissolve sulphate of iron, 2 oz., in 2 pints of distilled water, and add solution of persulphate of iron (B. P.), 51⁄2 fl. oz., then mix with solution of soda, 4 pints (B. P.), stirring well together. Boil the mixture, let it stand for 2 hours, stirring occasionally, then put it on a calico filter, and when the liquid has drained away wash the precipitate with distilled water till what passes through ceases to precipitate chloride of barium. Finally, dry the precipitate at a temperature not exceeding 120° Fahr.—Dose, 5 to 10 gr.
Ferrous Acetate. Fe(C2H3O2)2. Syn. Ferri acetas, L. Prep. 1. From freshly precipitated ferrous carbonate dissolved in dilute acetic acid.
2. By adding a solution of calcium acetate to another of ferrous sulphate, and evaporating the filtered liquid, out of contact with the air. Small, colourless, or pale-greenish needles or prisms, very soluble and prone to oxidation.
Ferrous Arsenate. Fe3(AsO4)2. Syn. Ferri arsenias, L. Prep. 1. From a solution of sodium arseniate, added to a solution of ferrous sulphate, the precipitate being collected, washed in a little cold water, and dried.—Dose, 1⁄20 to 1⁄12 gr., made into a pill; in lupus, psoriasis, cancerous affections, &c. Externally, combined with 4 times its weight of ferrous phosphate and a little water, as a paint to destroy the vitality of cancerous formations. An ointment (20 to 30 gr. to the oz.) is also used for the same purpose. They are all dangerous remedies in non-professional hands.