Preface; Symbols and notation; 1. The fluidised state; 2. The rise and coalescenece of bubbles in fluidised beds; 3. The formation of bubbles in fluidised beds; 4. The exchange between the bubble and particulate phases; 5. The stability of bubbles in fluidised beds; 6. The fluidised bed as a catalytic reactor; Appendix A1. Irrotational motion past a cylinder or sphere; Appendix A2. Percolation of fluid through a void in a particle bed; Appendix B. The pressure recovery in the wake below a spherical-cap bubble; Appendix C. Diffusion from the curved surface of a spherical-cap bubble; Bibliography; Index of authors; General index.