Phlogiston

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Phlogiston \Phlo*gis"ton\ (fl[-o]*j[i^]s"t[o^]n; 277), n. [NL.,
     fr. Gr. flogisto`s burnt, set on fire, fr. flogi`zein to set
     on fire, to burn, fr. flo`x, flogo`s, a flame, blaze. See
     {Phlox}.] (Old Chem.)
     The former hypothetical principle of fire, or inflammability,
     regarded by Stahl as a chemical element; it is now known to


     be nonexistent.
     [1913 Webster + PJC]
  
     Note: This was supposed to be united with combustible
           (phlogisticated) bodies and to be separated from
           incombustible (dephlogisticated) bodies, the phenomena
           of flame and burning being the escape of phlogiston.
           Soot and sulphur were regarded as nearly pure
           phlogiston. The essential principle of this theory was,
           that combustion was a decomposition rather than the
           union and combination which it has since been shown to
           be. This theory is now discredited and superseded by
           the theory of chemical reaction between oxidizable
           substances and oxidants as an explanation of combustion
           [1913 Webster + PJC]

From WordNet (r) 2.0 [wn]:

  phlogiston
       n : a hypothetical substance once believed to be present in all
           combustible materials and to be released during burning