The Measurement of Drift Velocities and Longitudinal Diffusion Coefficients. The Measurement of Transverse Diffusion Coefficients. Stationary Afterglow Techniques. Kinetic Theory of Mobility and Diffusion. Some Accurate Theroretical Results. Interaction Potentials and Transport Coefficients. Special Topics and Applications of the Theory. Index of Experimental Data on Gaseous Ion Mobilities and Diffusion Coefficients. Appendix I: Tables of Transport Cross Sections for Model Potentials. Appendix II: Tables of Properties Useful in the Estimation of Ion-neutral Interactions Energies. Author Index. Subject Index.