This book will be organized into eight chapters, each dealing with a key physical property of behaviour of solutions, so that a reader can obtain information on: hydrothermal experimental methods; available experimental data and the main features of properties behavior in a wide range of temperatures and pressures; possible ways of experimental data processing for obtaining the derivative properties. The original experimental data will be gathered in an appendix to each chapter and placed on a CD. The tables with the experimental data will be arranged in the appendix in alphabetical order by nonaqueous components and accompanied by the summaries of experimental methods, equipment and accuracy of given measurements.