(6) in mic. salt.  As in borax.

  (7) with carb. soda.  In the reducing flame is reduced, yielding
                         metallic antimony.

  (8) Special reactions.  As native antimony.

* * * * *

ARSENIC.

* * * * *

Mineral.  Native arsenic

Formula.  As.

Behavior

  (1) in glass-bulb.  Sublimes without fusion and recondenses as a
                         dark grey metallic sublimate, sometimes
                         leaving a small residue.

  (2) in open tube.  If gently heated in a good current of air
                         passes off as AsO^{3}, which is partly
                         condensed as a white sublimate in the upper
                         part of the tube.

  (3) on charcoal.  Passes off as AsO^{3}, which thinly incrusts
                         the charcoal beyond the assay.

  (4) in forceps.  Colors the flame blue.

  (5) in borax. —­

  (6) in mic. salt. —­

  (7) with carb. soda. —­

  (8) Special reactions. —­

* * * * *

Mineral.  Realgar

Formula.  AsS^{2}.

Behavior

  (1) in glass-bulb.  Fuses, enters into ebullition and is
                         sublimed as a transparent red sublimate.

  (2) in open tube.  Gently heated passes off as SO^{2} and
                         AsO^{3}, the latter of which is redeposited
                         in the upper part of the tube.

  (3) on charcoal.  Fuses and passes off as arsenious and
                         sulphurous acids.

  (4) in forceps.  Fuses and colors the flame blue.

  (5) in borax. —­

  (6) in mic. salt. —­

  (7) with carb. soda.  As on charcoal, except that the S combines
                         with the alkali forming NaS, which on silver
                         gives the sulphur reaction.

  (8) Special reactions. —­

* * * * *

Mineral.  Orpiment

Formula.  AsS^{3}.

Behavior

  (1) in glass-bulb.  As the preceding, except that the sublimate
                         is of a dark yellow color when cold.

  (2) in open tube.  As the preceding.

  (3) on charcoal.  As the preceding.

  (4) in forceps.  As the preceding.

  (5) in borax. —­

  (6) in mic. salt. —­

  (7) with carb. soda.  As the preceding.

  (8) Special reactions. —­

* * * * *