(8) Special reactions. With nitrate of cobalt, gives the magnesia reaction * * * * * Mineral. Epsomite Formula. [.Mg][...S] + 7[.H]. Behavior (1) in glass-bulb. Evolves water having an acid reaction on test paper. (2) in open tube. -- (3) on charcoal. Gives of HO and SO^{3}, shines brilliantly, and becomes alkaline and caustic. (4) in forceps. V. As on charcoal. (5) in borax. Behaves as magnesia. (6) in mic. salt. As in borax. (7) with carb. soda. The alkali is absorbed leaving the magnesia on surface of the charcoal. Gives the sulphur-reaction on silver. (8) Special reactions. The magnesian residue obtained on treating with carbonate of soda (7), assumes a flesh-tint, when treated with cobalt. * * * * * Mineral. Boracite Formula. [.Mg][...B]^{2} + 2[.Mg][...B]. Behavior (1) in glass-bulb. Occasionally gives off a trace of water. (2) in open tube. -- (3) on charcoal. Fuses with intumescence to a white crystalline bead. (4) in forceps. I. As on charcoal. Colors the flame green. (5) in borax. Fuses easily to a clear bead, which is crystalline, when containing much of the mineral, and is usually slightly tinted by iron. (6) in mic. salt. As in borax. (7) with carb. soda. With a small quantity of alkali fuses to a clear bead on cooling. With a larger quantity gives a clear, uncrystallizable bead. (8) Special reactions. -- * * * * * Mineral. Magnesite Formula. [.Mg][..C]. Behavior (1) in glass-bulb. Sometimes gives off a small quantity of water. (2) in open tube. -- (3) on charcoal. Is infusible. With cobalt-solution, assumes a dusky flesh tint. (4) in forceps. -- (5) in borax. Behaves as magnesia. Sometimes a slight iron-reaction. (6) in mic. salt. As in borax. (7) with carb. soda. Fuses to a bead, the soda is then absorbed, leaving an infusable mass of magnesia. (8) Special reactions. The magnesian residue obtained by fusing with carbonate of soda gives the magnesian-reaction with nitrate of cobalt. Dissolves with effervescence in warm HCl. * * * * * Mineral. Mesitine spar Formula. ([.Mg][.Fe][.Mn])[..C]. Behavior