Introduction. Water: Measurement of Sound Velocity. The Dependence of Velocity of Sound on Density and Compressibility. The Relationship Between Velocity and Attenuation--Conditions of High Attenuation. The Compressibility of Solute Molecules. Multiphase Media: Apparatus. Determining Composition in the Absence of Phase Changes. Following Phase Transitions. Determination of Solid Fat Content. Crystal Nucleation. The Solution-Emulsion Transition and Emulsion Inversion. Determination of Emulsion Stability by Ultrasound Profiling. Summary. Scattering of Sound: Theories of Sound. A Comparison of Electromagnetic and Acoustic Propagation. Scattering Theory. Scattering from Bubbles. Advanced Techniques: ParticleSizing. Propagation in Viscoelastic Materials. Bubbles and Foams. Automation and Computer Tools. Appendix: Basic Theory. MathCad Solutions of the Explicity Scattering Expressions. Glossary. Bibliography. Index. Table of Tables. Table of Figures.