Understanding chemical reactivity has been the permanent concern of chemists from time immemorial. If we were able to understand it and express it quantitatively there would practically remain no unsolved mystery, and reactions would be fully predictable, with their products and rates and even side reactions. The beautiful developments of thermodynamics through the 19th century supplied us with the knowledge of the way a reactions progresses, and the statistical view initiated by Gibbs has progressively led to an unders tanding closer to the microscopic phenomena. But is was always evident to all that these advances still left our understanding of chemical reactivity far behind our empirical knowledge of the chemical reaction in its practically infinite variety. The advances of recent years in quantum chemistry and statistical mechanics, enhanced by the present availability of powerful and fast compu ters, are very fast changing this picture, and bringing us really close to a microscopic understanding of chemical equilibria, reaction rates, etc.... This is the reason why our Society encouraged a few years ago the initiative of Professor Savo Bratos who, with a group of French colleagues, prepared an impressive study on "Reactivite chimique en phase liquide," a prospective report which was jointly published by the Societe Fran"

The presence of freely moving charges gives peculiar properties to electrolyte solutions, such as electric conductance, charge transfer, and junction potentials in electrochemical systems. These charges play a dominant role in transport processes, by contrast with classical equilibrium thermodynamics which considers the electrically neutral electrolyte compounds. The present status of transport theory does not permit a first prin ciples analys1s of all transport phenomena with a detailed model of the relevant interactions. Host of the models are still unsufficient for real systems of reasonable complexity. The Liouville equation may be adapted with some Brownian approximations to problems of interact ing solute particles in a continuum (solvent>; however, keeping the Liouville level beyond the limiting laws is an unsolvable task. Some progress was made at the Pokker-Planck level; however, despite a promising start, this theory in its actual form is still unsatis factory for complex systems involving many ions and chemical reac tions. A better approach is provided by the so-called Smoluchowski level in which average velocities are used, but there the hydrodyna mic interactions produce some difficulties. The chemist or chemical engineer, or anyone working with complex electrolyte solutions in applied research wants a general representa tion of the transport phenomena which does not reduce the natural complexity of the multicomponent systems. Reduction of the natural complexity generally is connected with substantial changes of the systems."