  We derive envelope equations which generate the Maxwell-Lorentz model and
describe the interaction of optical pulses with plasmonic oscillations in metal
nanoparticle composites. A family of solitary wave solutions is found which is
analogous to self-induced transparency in Maxwell-Bloch. The evolution of
incident optical pulses is studied numerically as are the collision dynamics of
the solitary waves. These simulations reveal that the collision dynamics vary
from near perfectly elastic to highly radiative depending on the relative phase
of the initial pulses.
