The phenomena of oscillations, travelling waves, and chaos in reacting chemical systems began as curiosities but now support an active, international research field. This book shows how these "exotic" patterns arise from the underlying chemical mechanisms. The origin of "chemical feedback" is revealed using three example reactions: the isolate-reductant (Landolt) reaction, the Belousov-Zhabotinsky reaction, and the combustion of hydrogen. Thermal feedback is also discussed. These mechanisms lead to clock reactions and travelling reaction fronts, thermal runaway, and flames; to oscillations...