The suggestion by Dr. Franklin S. Harris, Jr. , that these books be written arose pursuant to the editor's plaints that despite the implicitly or explicitly ack­ nowledged importance of both aerosols and particulate matter in innumerable domains of technology and human welfare, investigations of these subjects were generally not supported independently of the narrowest conceivable domains of their appli­ cations. Frank Harris, who has long been a contributor in one of the important domains of aerosol macrophysics, atmospheric optics, challenged the editor to elaborate his views. Ideally, they would have taken the form of a monograph; however, there is as yet an insufficient body of information to present a unified treatment. At the same time, substantial efforts are in progress in the component fields to hold the promise for the emergence of unifying elements which will even­ tually facilitate their presentation to be made with a high degree of integrity. There are numerous pertinent and systematic tie-ins between project-oriented aerosol work and basic physical investigations which are themselves quite closely akin to much classical and current work in physical science. The most significant aspect of these tie-ins is their potential for making substantial contributions to the functional needs of the applications areas while stimulating significant questions of basic physics. For this to be possible, it is necessary that the most relevant areas of physics be identified in such a manner as to make clear their re­ levance for aerosol-related studies and vice versa.

1. Introduction: The Domains of Aerosol Physics.- 1.1 The Aerosol Concept.- 1.2 Aerosol Physics.- 1.3 The Scope and Impact of Aerosols: Selected Fields.- References.- 2. The Kinetics of Ultrafine Particles.- 2.1 Aerosol System Parameters.- 2.2 Evolution of an Aerosol of Ultrafine Particles.- 2.3 Transfer Processes to Single Particles.- 2.4 Conclusion.- References.- 3. Classical and Statistical Theories of Gas-Surface Energy Transfer.- 3.1 A Simple Example: Driven-Oscillator Model.- 3.2 Classical Mechanical Treatment of Gas-Solid Collisions.- 3.3 Generalized Langevin Treatment of Gas-Surface Dynamics.- 3.4 Sample Results.- 3.5 Conclusion.- References.- 4. Inelastic Light Scattering.- 4.1 Overview.- 4.2 Elastic Scattering.- 4.3 Incoherent Inelastic Scattering.- 4.4 Coherent Inelastic Scattering.- 4.5 Resonance Effects.- 4.6 Summary and Conclusions.- References.- 5. Survey of Aerosol Interaction Forces.- 5.1 The Chemical Physics of Aerosol Particle Interactions.- 5.2 Kinetic Theory and Aerosol Interaction Forces.- 5.3 Electrostatic Interaction Forces.- 5.4 Van der Waals Interactions of Microparticles.- 5.5 Summary and Conclusion.- References.