Preface1. GenerallntroductionReferences2. Laboratory Studies2.1 Introduction2.2 Infrared Spectroscopy2.3 Mixedlces2.4 Silicate2.4.1 Structure of Silicate2.4.2 Silicate Studies2.4.2.1 Condensation2.4.2.2 EJfect of Environment2.4.2.3 Silicon Nano-crystals2.4.2.4 OpticalConstants2.5 Carbon2.5.1 Forms of Carbon2.5.2 Carbon Studies2.6 Polycyclic Aromatic Hydrocarbons ��PAHs��2.6.1 Spectra2.6.2 Mass Spectra2.6.3 Steller Environment2.6.4 Diffuse Interstellar Bands2.7 Optical Properties of Materials2.7.1 Theoretical Considerations2.7.2 Laboratory Measurements2.7.3 Mass Absorption Coefficient2.7.4 Microwave Scattering2.8 Microgravity Studies2.9 Nucleation2.10 Coagulation and Aggregation2.11 Other Dust StudiesReferences3. Interstellar Dust3.1 Introduction3.2 Estimate of Amount of Extinction3.3 Effect on Derived Distances3.4 Amount of Absorbing Material3.5 Nature of Dust3.5.1 Meanlnterstellar Reddening Curve3.5.2 Theoretical Extinction Curve3.5.3 Variations in the Interstellar Extinction Curve3.6 Interstellar Polarization3.7 Scattered Light3.7.1 Diffuse Galactic Light3.7.2 Reflection Nebulae3.7.3 The Extended Red Emission3.8 ElementalDepletion3.9 Diffuse Interstellar Bands3.10 Infrared Spectral Features3.10.1 Diffuse Interstellar Medium3.10.2 HH Region3.10.3 Reflection Nebulae3.10.4 Molecular Clouds3.10.5 Processes in Molecular Clouds3.10.6 Young Massive Protostar3.10.7 Star-Form.ing Regions3.11 Galactic Centre3.11.1 Extinction Law3.12 Sources of Dust3.13 Detection of Interstellar Dust��in-situ3.13.1 Spacecraft Studies3.13.2 Presolar Grains���� 4. Cometary Dust5. InterplanetaryDust6. Circumstellar Dust7. Extragalactic Dust8. EpilogueIndex