Changes in several solid state properties are expected when moving from the bulk crystal to small particles. The fundamental problems of the electronic band structure and the lattice vibration spectrum of particles having only 102 to 104 atoms are still in the beginning theoretical stages. Various anomalies should occur if the mean electronic level spacing exceeds thermal or photon or magnetic excitations. The recent widespread interest on surface excitations (surface phonons and plasmons) in small particles arises from the possibilities of observing the effects with infrared absorption and Raman and neutron scattering.