This book represents a revision and expansion of an earlier set of diagrams for tempera 0 0 tures from 25 to 300 C along the equilibrium vapor-liquid curve for H 0 (Helgeson, Brown, 2 and Leeper, 1969). The activity diagrams summarized in the following pages were generated over a six year period from 1977 to 1983 in the Laboratory of Theoretical Geochemistry (oth erwise known as Prediction Centra ) at the University of California, Berkeley. They represent the culmination of research efforts to generate a comprehensive and internally consistent set of thermodynamic data and equations for...