* * * * * BISMUTH. * * * * * Mineral. Native bismuth Formula. Bi. Behavior (1) in glass-bulb. -- (2) in open tube. Fuses and is converted into a yellow oxide. (3) on charcoal. Fuses to a bead and incrusts the charcoal with oxide. (4) in forceps. -- (5) in borax. The oxide formed upon charcoal gives the bismuth reactions. (6) in mic. salt. As in borax. (7) with carb. soda. -- (8) Special reactions. -- * * * * * Mineral. Bismuthine Formula. BiS. Behavior (1) in glass-bulb. -- (2) in open tube. Fuses with ebullition and gives of S and SO^{2}. (3) on charcoal. Fuses with much spirting and in the reducing flame yields a metallic bead and incrusts the charcoal with oxide. (4) in forceps. -- (5) in borax. The oxide obtained upon charcoal gives the bismuth reactions. (6) in mic. salt. As in borax. (7) with carb. soda. As alone on charcoal. The fused alkali gives the sulphur reaction on silver. (8) Special reactions. -- * * * * * Mineral. Bismuthblende Formula. [...Bi=]^{2}[...Si]^{3}. Behavior (1) in glass-bulb. Turns yellow and, when strongly heated, fuses. (2) in open tube. -- (3) on charcoal. Fuses with ebullition to a brown globule forming an incrustation of [...Bi=] on the charcoal. (4) in forceps. I. Fuses with ease to a yellow bead, coloring the outer flame bluish green, especially if moistened with HCl. This color is due to [.....P]. (5) in borax. Gives the bismuth and also an iron reaction. (6) in mic. salt. As in borax, but leaves a silicious skeleton. (7) with carb. soda. Fuses to a yellow mass. The bismuth is then reduced to the metallic state and partially volatilized, incrusting the charcoal beyond. (8) Special reactions. -- * * * * * Mineral. Tetradymite Formula. Bi, Te, S. Behavior (1) in glass-bulb. Occasionally decrepitates and then fuses, forming a greyish white sublimate immediately above the mineral fragment.