lime light \lime" light`\, limelight \lime"light`\
   An intense light produced by heating lime. See Calcium
   light under Calcium.
   [1913 Webster]

Drummond light \Drum"mond light`\ [From Thomas Drummond, a
   British naval officer.]
   A very intense light, produced by turning two streams of gas,
   one oxygen and the other hydrogen, or coal gas, in a state of
   ignition, upon a ball of lime; or a stream of oxygen gas
   through a flame of alcohol upon a ball or disk of lime; --
   called also oxycalcium light, or lime light.
   [1913 Webster]

   Note: The name is also applied sometimes to a heliostat,
         invented by Drummond, for rendering visible a distant
         point, as in geodetic surveying, by reflecting upon it
         a beam of light from the sun.
         [1913 Webster]

Calcium \Cal"ci*um\ (k[a^]l"s[i^]*[u^]m), n. [NL., from L. calx,
   calcis, lime; cf F. calcium. See Calx.] (Chem.)
   An elementary substance; a metal which combined with oxygen
   forms lime. It is of a pale yellow color, tenacious, and
   malleable. It is a member of the alkaline earth group of
   elements. Atomic weight 40. Symbol Ca.
   [1913 Webster]

   Note: Calcium is widely and abundantly disseminated, as in
         its compounds calcium carbonate or limestone, calcium
         sulphate or gypsum, calcium fluoride or fluor spar,
         calcium phosphate or apatite.
         [1913 Webster]

   Calcium light, an intense light produced by the
      incandescence of a stick or ball of lime in the flame of a
      combination of oxygen and hydrogen gases, or of oxygen and
      coal gas; -- called also Drummond light and lime
      light.
      [1913 Webster +PJC]