The Collaborative International Dictionary of English v.0.48:

Pyroxyle \Py*rox"yle\, n. [Cf. F. pyroxyle. See Pyroxylic,
   -yl.]
   [1913 Webster] Pyroxylic \Pyr`ox*yl"ic\, a. [Pyro- + Gr. ?
   wood.] (Old Chem.)
   Derived from wood by distillation; -- formerly used in
   designating crude wood spirit.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

pyroxylin \py*rox"y*lin\, n. (Chem.)
   A substance resembling gun cotton in composition and
   properties, but distinct in that it is more highly nitrified
   and is soluble in alcohol, ether, etc.; -- called also
   pyroxyle.
   [1913 Webster]