Source : Webster's Revised Unabridged Dictionary (1913)

Iodine \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.