(1) in glass-bulb. As magnesite. (2) in open tube. -- (3) on charcoal. Is infusible. Assumes a deep brown color. (4) in forceps. V. (5) in borax. Gives the iron and manganese-reaction. (6) in mic. salt. As in borax. (7) with carb. soda. As magnesite, but the residual mass has a dark color from iron and manganese. (8) Special reactions. Dissolves with effervescense in warm HCl. With carbonate of soda and nitre gives a manganese-reaction. * * * * * ALUMINA. * * * * * Mineral. Sapphire Corundum Emery Formula. [...Al=]. Behavior (1) in glass-bulb. -- (2) in open tube. -- (3) on charcoal. -- (4) in forceps. V. (5) in borax. In fine powder dissolves slowly to a colorless glass. (6) in mic. salt. As in borax. (7) with carb. soda. -- (8) Special reactions. In fine powder moistened with cobalt-solution and heated yields a blue color. * * * * * Mineral. Websterite Formula. [...Al][...S] + 9[.H]. Behavior (1) in glass-bulb. Gives off water, and, when heated to incipient redness, sulphurous acid. (2) in open tube. -- (3) on charcoal. Gives off water and SO^{3}, leaving an infusible mass. (4) in forceps. V. (5) in borax. Behaves as alumina. (6) in mic. salt. As in borax. (7) with carb. soda. Yields an infusible mass, which laid on silver and moistened, produces a black stain. (8) Special reactions. Fused with potassa in platinum has no action on silver. Cobalt-solution produces the alumina reaction. * * * * * Mineral. Native Alum Formula. [.R][...S] + [...Al][...S]^{3} + 24[.H]. Behavior (1) in glass-bulb. Intumesces greatly and gives off much water. Strongly heated, evolves SO^{3}, which reddens litmus. (2) in open tube. -- (3) on charcoal. Intumesces and become infusible. (4) in forceps. V. Colors the flame violet if a potassa alum--yellow if soda--be present. (5) in borax. Dissolves and gives the iron and manganese reaction, if these oxides be present. Otherwise the bead is colorless. (6) in mic. salt. As in borax.