NICKEL AND COBALT. * * * * * Mineral. Millerite Formula. NiS. Behavior (1) in glass-bulb. -- (2) in open tube. Evolves SO^{2}. (3) on charcoal. Fuses with much ebullition to a magnetic bead. (4) in forceps. -- (5) in borax. The roasted mineral gives a nickel reaction, slightly modified by small quantities of iron and copper. (6) in mic. salt. As in borax. (7) with carb. soda. Fuses to a slaggy mass, which on silver gives the sulphur reaction. (8) Special reactions. -- * * * * * Mineral. Coppernickel Formula. Ni^{2}As. Behavior (1) in glass-bulb. Gives off a little AsO^{3}. (2) in open tube. Gives off much AsO^{3} and some SO^{2} and falls to powder. (3) on charcoal. Fuses to a magnetic bead, with the evolution of arsenic, which colors the flame blue. (4) in forceps. -- (5) in borax. The arsenical bead obtained by fusing the mineral on charcoal, if fused upon the same support with borax successively added and removed, gives firstly an iron reaction, then cobalt if present, and lastly nickel. (6) in mic. salt. If the residual bead which has been treated with borax be further treated with microcosmic salt, the nickel reaction will be obtained and sometimes a slight copper reaction. (7) with carb. soda. -- (8) Special reactions. Affords a sublimate of metallic arsenic when treated with cyanide of potassium. * * * * * Mineral. Smaltine Formula. CoAs. Behavior (1) in glass-bulb. When strongly heated generally evolves metallic arsenic. (2) in open tube. Gives a crystalline sublimate of AsO^{3}. Also some SO^{2}. (3) on charcoal. Gives off fumes of arsenic, and fuses to a dark grey magnetic bead, very brittle, colors flame blue. (4) in forceps. -- (5) in borax. As the preceding, but the cobalt being in large excess requires some time for its perfect oxidation, before the nickel reaction is exhibited. (6) in mic. salt. Gives the cobalt reaction, and after the cobalt has been, removed that of nickel. (7) with carb. soda. -- (8) Special reactions. As the preceding. * * * * *