(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.

* * * * *

Mineral.  Glance cobalt

Formula.  CoS^{2} + CoAs.

Behavior

  (1) in glass-bulb. —­

  (2) in open tube.  As the preceding, but gives off more SO^{2}.

  (3) on charcoal.  Gives off S and As, and fuses to a magnetic
                         bead.  Colors flame blue.

  (4) in forceps. —­

  (5) in borax.  Gives a cobalt and slight iron reaction when
                         treated as the preceding minerals.

  (6) in mic. salt.  As in borax.

  (7) with carb. soda.  Gives a sulphur reaction of silver.

  (8) Special reactions.  As the preceding.