The temperatures and the enthalpies of both solid-solid and solid-liquid phase transition were collected from the original literature published from the end of the last century to early 1995. All the values were critically evaluated to provide recommended values in the cases where several experimental values were reported for the same phase transition. The accuracies of both the original and recommended values were determined and information was given regarding the sample purity and method of measurement. This volume should be of interest to a range of researchers, specialists and engineers working in the field of physical and organic chemistry, chemical engineering, electronics, material science, chemical aspects of energy technology and those developing predictive packages, and for universities.