Source : Webster's Revised Unabridged Dictionary (1913)

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}.

   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.

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.

   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.

   {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}.