This book is an extensive yet self-contained reference of single microparticle studies as they have been performed for many years by the authors. With the range of theoretical and experimental tools available it has become possible to use the many unique properties of droplets and small particles to investigate phenomena as diverse as, linear and nonlinear optics, solution thermodynamics, gas/solid and gas/liquid chemical reactions, transport properties such as gas phase diffusion coefficients, rate processes in the continuum and non-continuum regimes, trace gas uptake by aerosol droplets related to atmospheric chemistry and ozone depletion, phoretic phenomena, Raman spectroscopy, particle charge, evaporation and condensation processes. Throughout the book the main concern of the authors was to provide the reader with a visualization of the significance and application of the theory by experimental results.