The ancient Greeks believed that all matter was composed of four elements: earth, water, air, and fire. By a remarkable coincidence (or perhaps not), today we know that there are four states of matter: solids (e.g. earth), liquids (e.g. water), gasses (e.g. air) and plasma (e.g. ionized gas produced by fire). The plasma state is beyond the scope of this book and we will only look at the first three states. Although on the microscopic level all matter is made from atoms or molecules, everyday experience tells us that the three states have very different properties. The aim of this book is to examine some of these properties and the underlying physics.

The book contains the very latest information on all aspects of heat capacities related to liquids and vapours, either pure or mixed. The chapters, all written by knowledgeable experts in their respective fields, cover theory, experimental methods, and techniques (including speed of sound, photothermal techniques, brillouin scattering, scanning transitiometry, high resolution adiabatic scanning calorimetry), results on solutions, liquids, vapours, mixtures, electrolytes, critical regions, proteins, liquid crystals, polymers, reactions, effects of high pressure and phase changes. Experimental methods for the determination of heat capacities as well as theoretical aspects, including data correlation and prediction, are dealt with in detail. Of special importance are the contributions concerning heat capacities of dilute solutions, ultrasonics and hypersonics, critical behavior and the influence of high pressure.