All real solid surfaces are heterogeneous to a greater or lesser extent and this book provides a broad yet detailed survey of the present state of gas adsorption. Coverage is comprehensive and extends from basic principles to computer simulation of adsorption. Underlying concepts are clarified and the strengths and weaknesses of the various methods described are discussed. Key Features * Adsorption isotherm equations for various types of heterogeneous solid surfaces * Methods of determining the nature of surface heterogeneity and porosity from experimental data * Studies of phase behavior of gases absorbed on heterogeneous solid surfaces * Computer simulation of adsorption on heterogeneous solid surfaces.