from
The Collaborative International Dictionary of English v.0.48
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 This theory is now discredited and superseded by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]