This second volume in the HERCULES Course on Neutron and Synchrotron Radiation for Condensed Matter Studies is devoted to selected applications in physics and chemistry of solids, with the fourteen chapters ranging from general considerations of symmetry in condensed matter to the most recent developments in magnetic excitations and electron spectroscopies in high Tc superconductors. The subjects were chosen either for their basic importance or because of interesting new developments, while the fifteen authors were selected both for their high scientific expertise and their teaching skills.