(1) in glass-bulb. Sometimes decrepitates, fuses, and when very strongly heated, gives a red sublimate of [,,,Sb] with [...Sb], also sometimes a black sublimate of [,Hg] and occasionally [,,,As]. (2) in open tube. Fuses and gives off thick fumes of SbO^{3} and SO^{2}, also generally AsO^{3}, leaving a black infusible residue. If Hg be present, it is sublimed and condenses in the tube in small drops. (3) on charcoal. Fuses to a bead, which fumes strongly and incrusts the charcoal with SbO^{3}, and sometimes ZnO, which cannot be volatilized. Emits a strong smell of arsenic. (4) in forceps. -- (5) in borax. The residue obtained on charcoal thoroughly roasted gives a copper reaction, and when the latter has been removed by reduction upon charcoal, an iron reaction. (6) in mic. salt. As in the preceding. (7) with carb. soda. With this flux and a little borax yields a bead of metallic copper; on silver, the alkaline mass gives a sulphur reaction. (8) Special reactions. If the copper bead obtained by fusing upon carbonate of soda be cupelled with assay lead, a silver bead will be obtained. Or if dissolved in nitric acid and a drop or two of HCl added, a white precipitate of AgCl will be formed, which may be collected and reduced with carbonate of soda upon charcoal. * * * * * Mineral. Tennatite Formula. ([,Cu=][,Fe=])^{4}[,,,As]. Behavior (1) in glass-bulb. Decrepitates occasionally and gives a red sublimate of [,,,As]. (2) in open tube. Evolves [..S] and [...As], which condense and form a white sublimate. (3) on charcoal. Fuses to a magnetic bead giving of arsenical and sulphurous fumes. (4) in forceps. -- (5) in borax. As the preceding. (6) in mic. salt. As the preceding. (7) with carb. soda. Yields a copper bead and metallic iron in the form of a dark grey powder. The fused alkali gives the sulphur reaction. (8) Special reactions. -- * * * * * Mineral. Bournonite Formula. ([,Pb]^{2}[,Cu=])[,,,Sb]. Behavior (1) in glass-bulb. Decrepitates giving off sulfur and, when strongly heated, [,,,Sb] and [...Sb].