Limatura. E. Ferri Scobs. D.
Iron Filings and Wire.
Iron seems to be a metal that proves active in its metallic state; its filings may be given in the form of powder, conjoined to some aromatic, or what is perhaps more eligible, in the form of an electuary. The Mahometan practitioners are in the habit of prescribing them, in conjunction with ginger, and cummin seeds, in cases requiring tonics. Dose, grs. v to ʒss. Impurities. Iron filings should be carefully purified by the application of the magnet, since those obtained from the work-shops are generally mixed with copper and other metals. For pharmaceutical purposes, iron wire should be preferred, as being the most pure, since the softest iron only can be drawn, and Mr. Phillips has shewn us, in his experiments upon the “Ferrum Tartarizatum” that soft iron is more easily acted upon by Tartar.
FERRI SULPHAS. L. Sulphas Ferri. E.D.
Ferrum Vitriolatum. P.L. 1787. Sal Martis. P.L. 1745.
Sal, seu Vitriolatum Martis. P.L. 1720.
Sulphate of Iron, formerly Green Vitriol.
Qualities. Form, crystals, which are rhomboidal prisms, transparent, and of a fine green colour; when exposed to the air they effloresce, and at the same time become covered with a yellow powder, owing to the attraction of oxygen; when exposed to heat, they undergo watery fusion, and at a higher temperature, the acid is driven off and the peroxide of iron alone remains, which in commerce is known by the name of Colcothar. Chemical Composition. According to Dr. Thomson, it consists of 27·7 of sulphuric acid, 28·3 of protoxide of iron, and 45 of water; 8 parts, however, of this water, exist in combination with the oxide of iron. The Medicinal Dynameter will shew the proportion of protoxide in any given weight of this salt. Solubility. It is soluble in two parts of water at 60°, and three-fourths at 212°. The solution reddens vegetable blues. It is insoluble in alcohol; when however the iron is farther oxidized, it becomes soluble in that menstruum.[[507]] Incompatible Substances. Every salt whose base forms an insoluble compound with sulphuric acid; the earths, the alkalies and their carbonates; borate of soda; nitrate of potass; muriate of ammonia; tartrate of potass and soda; acetate of ammonia; nitrate of silver; sub-acetate and acetate of lead; and Soaps. Whether the medicinal virtues of a salt of iron are injured by combination with astringent vegetable matter, seems to admit of doubt. Such substances have been usually ranked amongst the incompatibles, but I am disposed to think without sufficient grounds, for I have frequently witnessed the salutary effects of iron when exhibited in this questionable state of combination—may not the absorbents be more disposed to take up iron, when combined with vegetable matter, than when it is presented in a more purely mineral form?[[508]] Medicinal Uses. Tonic, astringent, emmenagogue, and anthelmintic; in large doses, it occasions griping in the bowels. Dose, gr. j to v, combined with rhubarb, or some bitter extract. (form: 72, 87.) If given in solution, the water should be previously boiled, or the oxygen contained in the atmospherical air, which is diffused through it, will partially convert the salt into an oxy-sulphat, and render it insoluble. As an external astringent it is useful in the aphthæ of children.[[509]] Officinal Prep. Mist: Ferri comp: L. (K) Pil: Ferri comp: L. (J).
FERRUM AMMONIATUM. L. Murias
Ammoniæ et Ferri. E.D.