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Order XXVII.— IRON AND ITS COMPOUNDS.1. FER'RUM, L. E. D. [U. S.]—IRON.

(Ramcnta. £.—Filum; Limatura, E.— Fjla ; Scobs, Oxydi Squammse, D.)[Fern FJtum; Iron Wire, Ferri flamenta, Iron Filings, U. S.J

History. —This metal (called by the alchymists Mars) was known in the mostancieht firries.' It was employod medicinally at a very early period, namely,above 3200 years ago. Indeed, it appears to have been the first mineral usedinternally; and a cürious anecdote is given of its introduction into medicine.Melampus (a shepherd'supposed to possess supernatural powers) being applied toby Iphicles, son of Philacus, for a remedy against impotence, slaught'ered two bulls,the intestines of which he cut to pieces, in order to attract birds to an argury.Among the animals which came to the feas'c was a vulture, from whom Melam-pus pretended to learn tliat his patieht, when a boy, had stuck a knife, wet withthe blood of some rams, into a consecrated chestnut-tree, and the bark had subse-quently enveloped it. The vulture also indicated the remedy, namely, to procurethe knife, scra.pe off the rast, and drink it in wine, for the space of ten days, bywhich time Iphicles would be lusty, and capable of begetting children. Theadvice thus given by Melampus is said to have been foliowed by the young princewith the most perfect success! (Le Clcrc, Hut. de la Medecine.)

Natural History. —Iron is met with in both kingdorns of nature.

et. In the Inobganized Kingdom. —Fcw minerals are free from iron. It is found i11 themetallic state (native iron,) in combination with oxygen (hamutite, micaceous iron, brown iron«tone,.and magnctic iron ore,) with sulphur (iron pyrites, and magnelic pyrites,) with chlorine(pyrosmalüe,) and with oxygen and an acid (caibonate, phosphate, sulphatc, arsenifde, iung.State, tantatate, titaniale, Chromate, Oxalate, and siticate.)

ß. In tue Ojiganized KiNGDoni.—^It occurs in the ashes of most plants, and in- the bloodand some other parts of animals.

Extraction. —In Sweden, iron is extractcd from magnetic iron ore am] mica-ceous iron: in England, principally from clay iron ore (carbonale of iron.)

Clay iron ore (technically called Mine) is btirned with coal in large heaps, bywtiicn it loses carbonic acid, water, and sulphur. Itis then smelted with a flux (inSouth Wales this is limestone; in the forest of Dean, clay;) and cofc.e. The smeltediron is run into moulds, and is then called Cast Iron {Ferrum fusum) or PigIron. This contaihs carbon, oxygen, silicön, and often sulphur and phos-phorus. To separate these, it is submitted to several pröcesses (called refining,puddling, and welding,) by which it is converted into Wrought Iron (Ferrumcusum.y

Properties. —The primary form of the ctystals of native iron is the reguläroctohedron. Pure iron has a whitish gray colour, or, according to Bcrzelius, isalmost silver white. When polished it has much brilliancy: its taste is peculiarand stvptic; when rubbed it becomes odorous. Its ductility and tcnacity aregreat; its malleability comparatively small. Its sp. gr. is 7-788, but diminishesby rolling or drawing. It is attracted by the magnet, and several of its Com-pounds are capable of becoming permanent magnots; but pure iron retains itsmagnetic property for ashort time only. It requires a very intense heat tofuse it;and it is not volatile at any known temperature; while in' the softened state, pre-vious to melting, it is capable of being welded. Its eqüivalent or atomic weightis 28.

Characteristics. —Iron rcadily dissolves in dilüted sulphuric acid', with the

i Mmufacture of Iran, in the Li'drtrij of Uscful Knowledge; also, Treatisc on fron aili Steel, in Lurdner'sQyctopaidia.

Vol. I.— 86