Source : Webster's Revised Unabridged Dictionary (1913)

Bougie d'ecimale \Bou*gie" d['e]`ci`male"\ [F., lit., decimal
   candle.]
   A photometric standard used in France, having the value of
   one twentieth of the Violle platinum standard, or slightly
   less than a British standard candle. Called also {decimal
   candle}.