Diffusion-controlled reactions in solution -- Reactions between ions in solution -- Long-range transfer effects and diffusion-controlled reactions -- Rotational diffusion effects -- The escape probability of an isolated pair -- Geminate ion-pair recombination -- A critique of the diffusion equation and molecular pair treatments -- Refinements to the diffusion equation analysis to include many-body effects -- The variational principle -- Phenomenological Brownian motion -- The kinetic theory applied to chemical reactions in solutions.