\I"o*dine\ (?; 104), n. [Gr. ? violetlike; ? a violet + ?
form: cf. F. iode, iodine. The name was given from the violet
color of its vapor. See {Violet}, {Idyl}.] (Chem.)
A nonmetallic element, of the halogen group, occurring always
in combination, as in the iodides. When isolated it is in the
form of dark gray metallic scales, resembling plumbago, soft
but brittle, and emitting a chlorinelike odor. Symbol I.
Atomic weight 126.5. If heated, iodine volatilizes in
beautiful violet vapors.
Note: Iodine was formerly obtained from the ashes of seaweed
      (kelp or varec), but is now also extracted from certain
      natural brines. In the free state, iodine, even in very
      minute quantities, colors starch blue. Iodine and its
      compounds are largely used in medicine (as in
      liniments, antisyphilitics, etc.), in photography, in
      the preparation of aniline dyes, and as an indicator in
      titration.
{Iodine green}, an artificial green dyestuff, consisting of
   an iodine derivative of rosaniline; -- called also {night
   green}.
{Iodine scarlet}, a pigment of an intense scarlet color,
   consisting of mercuric iodide.
{Iodine yellow}, a brilliant yellow pigment, consisting of
   plumbic iodide.