The oxides of manganese fuse with microcosmic salt in the oxidation flame, to a clear brownish-violet bead, which appears reddish-violet while cooling. This bead does not become opaque when overcharged with manganese. As long as it is kept in fusion a continued boiling or effervescence takes place, produced by the expulsion of oxygen, in consequence of the fact that the microcosmic salt cannot dissolve much sesquioxide, while the rest is reduced to protoxide, is re-oxidated, and instantly again reduced. If the manganese is present in such a minute quantity as not to perceptibly tinge the bead, the color may be made to appear by the contact of a crystal of nitre while hot. The bead foams up upon the addition of the nitre, and the foam appears, after cooling, of a rose-red or violet color. In the reduction flame the bead sometimes becomes colorless. The oxides of manganese fuse with carbonate of soda upon platinum foil or wire, to a clear green bead, which appears bluish-green and partially opaque when cold (manganate of soda NaO + MnO^{3}). A very minute trace of manganese will produce this green color. The oxides of manganese cannot be reduced upon charcoal with carbonate of soda before the blowpipe. The soda is absorbed, and (MnO + Mn^{2}O^{3}) is left. GROUP FIFTH.--IRON, COBALT, NICKEL. The oxides of this group are reduced to the metallic state when fused with carbonate of soda upon charcoal in the reduction flame. Metals when thus reduced form powders, are not fusible or volatile in the blowpipe flame, but they are attracted by the magnet. Furthermore, these oxides are not dissolved by carbonate of soda in the oxidation flame, but they produce colored beads with borax and microcosmic salt. (_a._) _Iron._--It occurs in great abundance in nature. It is found in several places in America in the metallic state, and it likewise occurs in the same state in meteors. It occurs chiefly as the oxide (red hematite, brown hematite, magnetic oxide, etc.), and frequently in combination with sulphur. Iron also forms a constituent of the blood. Metallic iron is of a grey color, and presents the metallic lustre vividly when polished. It is very ductile, malleable, and tenacious. It is very hard at common temperatures, but soft and yielding at a red heat. In dry and cold air, iron does not oxidize, but when the air is dry and moist, it oxidizes rapidly. This likewise takes place with great rapidity when the metal is heated to redness. When submitted to a white heat iron burns with brilliant scintillations.