Ferrous Oxide. FeO. Syn. Protoxide of iron, Ferri protoxydum, L. This substance is almost unknown in a pure state, from its extreme proneness to absorb oxygen and pass into the sesquioxide.
Ferrous Phosphate. Syn. Phosphate of iron, Neutral p. of protoxide of iron, Bimetallic ferrous orthophosphate (Odling); Ferri phosphas (Ph. U. S.), L. A salt formed from ordinary or tribasic phosphoric acid.
Prep. (B. P.) Ferrous sulphate, 3; sodium phosphate, 21⁄2; sodium acetate, 1; boiling distilled water, 80; dissolve the sulphate and sodium salts, each in half the water, mix, and stir carefully, filter through calico, wash with hot distilled water until it ceases to give a precipitate with barium chloride, dry at a heat not exceeding 120° Fahr. (Ph. U. S.) Ferrous sulphate, 5 oz.; sodium phosphate, 6 oz.; dissolve each separate in 2 quarts of water, mix the solutions, and after repose for a short time wash and dry the precipitate.
Prop., &c. A slate-coloured powder; insoluble in water; soluble in dilute nitric and hydrochloric acid.—Dose, 5 to 10 gr.; in amenorrhœa, diabetes, dyspepsia, scrofula, &c.; and externally, as an application to cancerous ulcers.
Ferrous Sulphate. FeSO4.7Aq. Syn. Protosulphate of iron, Sulphate of iron, Copperas, Green vitriol, Shoemaker’s black; Ferri sulphas (B. P., Ph. L. E. & D.), Vitriolum ferri. The crude sulphate of iron or green vitriol of commerce (FERRI SULPHAS VENALIS, Ph. L.) is prepared by exposing heaps of moistened iron pyrites or native bisulphuret of iron to the air for several months, either in its unprepared state or after it has been roasted.
When decomposition is sufficiently advanced, the newly formed salt is dissolved out with water, and the solution crystallised by evaporation. In this state it is very impure. The ferrous sulphate or sulphate of iron employed in medicine is prepared as follows:—
Prep. (B. P.) Iron wire, 4; sulphuric acid, 4; distilled water, 30. Pour the water on the iron, add the acid, and when the disengagement of gas has nearly ceased, boil for ten minutes. Filter through paper. Allow to stand twenty-four hours, and collect the crystals. Sulphuric acid, 1 fl. oz.; water, 4 pints; mix, and add of commercial sulphate of iron, 4 lbs.; iron wire, 1 oz.; digest with heat and occasional agitation until the sulphate is dissolved, strain whilst hot, and set aside the liquor that crystals may form; evaporate the mother-liquor for more crystals, and dry the whole.
Dissolve the transparent green crystals of the impure sulphate of iron in their own weight of water, acidulated with sulphuric acid, and re-crystallise.
The formula of the Ph. U. S. is similar.
Dried; Ferri sulphas exsiccata, B. P.; Ferri sulphas exsiccatum—Ph. E., F. s. siccatum—Ph. D. From ferrous sulphate, heated in a shallow porcelain or earthen vessel, not glazed with lead, till it becomes a greenish-grey mass, and then reduced to powder. The heat should be that of an oven, or not exceeding 400° Fahr. Five parts of the crystallised sulphate lose very nearly 2 parts by drying.