The behaviour and hence the possible impact of trace gases and solids in the atmosphere is now of major concern amongst scientists. This book is a result of discussions between members of the IUPAC Commission on Solubility Data and the IUPAC Commission on Atmospheric Chemistry extending over several years. The book provides a broad survey and theoretical basis of many aspects of the behaviour of stable and unstable chemicals in the atmosphere. There is special emphasis on heterogeneous processes at all levels of the atmosphere. Modern techniques of investigation and of modelling such processes are discussed and many experimental data relating to interaction of gases with cloud droplets and with surfaces of solid particles are included. A detailed account of theoretical and practical aspects of Henry?s law constants, including their relationship to infinite dilution activity coefficients, is also presented. Experimental values of 15 inorganic and 153 organic stable compounds...