IRON LIQ′UOR. Syn. Pyrolignite of iron, Dyer’s acetate of i., Black liquor, Tar iron L.; Ferri acetas venalis, L. This article, so extensively used in dyeing, is a crude mixed acetate of the protoxide and sesquioxide of iron. It is usually prepared by one or other of the following methods:—
1. Old scraps of iron (hoops, worn-out tin-plate, &c.) are left in a cask of pyroligneous acid, occasional agitation being had recourse
to, until a sufficiently strong solution is obtained. By keeping the acid moderately warm in suitable vessels it will become saturated with the iron in a few days. With cold acid, on a large scale, forty days or more are required to complete the process.
2. A solution of pyrolignite or crude acetate of lime, is added to another of green copperas, as long as a precipitate is formed; after repose, the clear liquor is decanted.
IRON, REDUCED. Syn. Quevenne iron; Ferrum redactum (B. P.), Ferri pulvis, L.; Fer reduit, F. Prep. This preparation, which consists of metallic iron in a fine state of division mixed with a variable amount of magnetic oxide of iron, is made by passing perfectly dry hydrogen over peroxide of iron heated to redness in a gun-barrel.
Prop. A greyish-black powder, attracted by the magnet, and exhibiting metallic streaks when rubbed with firm pressure in a mortar. Rapidly absorbs oxygen, and must, therefore, be preserved from the air in well-stoppered bottles. It dissolves in hydrochloric acid with the evolution of hydrogen. 10 grains added to an aqueous solution of 50 grains of iodine and 50 grains of iodide of potassium, and digested with them in a small flask at a gentle heat, should leave not more than 5 grains undissolved, which should be entirely soluble in hydrochloric acid.
Uses. In medicine it is chiefly given to restore the condition of the blood in all anæmic states of the system. There is no pulverulent state of iron so convenient as this for children, as it has no taste, and only a very small dose is required.—Dose, 1 to 5 grains (children, 1⁄4 to 1 grain), in powder, pill, or between bread and butter.
Iron reduced by Electricity. See Electricity, Iron reduced by.
Iron, to remove Rust from Polished. Rust of iron may be removed from a polished grate by means of emery paper, or by scraping some Bath-brick to a fine powder, mixing it with a little oil and rubbing the spots well with a piece of flannel dipped in this mixture; after which some whiting should be applied by diligent friction. This operation requires daily repetition until the rust has disappeared. Steel fire-irons, fenders, &c., when put aside in the summer, should be previously smeared thinly over with a species of paraffin, known to druggists by the name of ‘vaseline’ or ‘cosmoline,’ or with grease, mercurial ointment, &c.
Iron, to remove the Stains of, from Marble. Rub on very cautiously (confining it to the surface only occupied by the spot) some strong hydrochloric acid, removing it directly the spot disappears. Should this cause any diminution in the polish, this may be restored by means of emery paper.