This research project is an experimental study of the solubility behavior of materials in solvents at what is known as "supercritical regions" of pressure and temperature. There is sufficient ground for the hypothesis that the changes in the solubilities of dissolved matter under such conditions can be exploited successfully to separate multicomponent mixtures (selectively) from each other. This experimental program will study the behavior of the solutes under supercritical conditions in a systematic manner.