(5) in borax. As the preceding; but when the copper has been removed by reducing on charcoal, the bead shows a strong iron color.
(6) in mic. salt. As the preceding, but the color in the oxidizing flame is green, owing to the presence of iron.
(7) with carb. soda. Yields a bead of metallic copper and some magnetic oxide of iron which remains on the charcoal. The fused gives a sulphur reaction on silver.
Formula. ([,Cu=][,Ag][,Fe][,Zn])^{ 4} ([,,,Sb][,,,As]).
(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.
(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.
(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.
(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.
(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.
(1) in glass-bulb. Decrepitates giving off sulfur and, when strongly heated, [,,,Sb] and [...Sb].
(2) in open tube. Evolves thick white fumes of [...Sb],[.....Sb] and [.Pb][...Sb]. Also [.S].