Colloque Weyl I was convened in June 1963 at the Catholic University of Lille to commemorate one hundred years of the study of metal-ammonia solutions. That meeting made it clear that Colloque Weyl should be continued in order to promote the fruitful exchange of ideas set in motion at Lille and at Cornell.

Theory of Electrons in Polar Fluids.- Discussion.- Metal-Ammonia Solutions: The Dilute Region.- Discussion.- The Effect of Electrolytes on the Hydrogen-Bonded Structure of Liquid Ammonia.- Discussion.- Magnetic Relaxation Properties of Dilute Solutions of Sodium in Liquid Ammonia.- Chemical Equilibria between Anions and the Ammoniated Electron.- Discussion.- Metal Solutions in Amines and Ethers.- Discussion.- Extinction Coefficients of Solutions of Alkali Metals in Amines.- Discussion.- Ultrafast Optical Processes.- Discussion.- Quasi-Free Electrons in Polar Liquids.- Discussion.- Spectra of the Ammoniated Electron in the Presence of Amide.- Discussion.- Raman Spectroscopy of Metal-Ammonia Solutions.- Raman Spectra of Dilute Metal-Ammonia Solutions.- General Discussion of Papers by SMITH/KOEHLER and DEBACKER et al.- Metal-Ammonia Solutions VIII. Infrared Spectroscopy of the Solvent.- Discussion.- Metal-Ammonia Solutions: Transition Range.- Appendix. A Percolation Process for Metal to Nonmetal Transition in Metal-Ammonia Systems.- Thermodynamics and Critical Phenomena in Metal-Ammonia Solutions.- Transport Properties of Lithium-Ammonia Solutions in the Intermediate Concentration Range.- General Discussion of Papers by LEPOUTRE, DAMAY and LELIEUR et al.- NMR Measurements of Self-Diffusion in Lithium-Ammonia and Sodium-Ammonia Solutions.- Discussion.- Cell e.m.f.’s in Metal-Ammonia Solutions.- Discussion.- Impedence Behavior of Metal-Ammonia Solid Metal Interface.- Discussion.- Absorption of Ultrasound in Metal-Ammonia Solutions.- Discussion.- The Electronic Structures of Disordered Materials.- Discussion.- Concentrated M-NH3 Solutions: A Review.- Discussion.- Nuclear Magnetic Resonance Studies of Cesium-Ammonia Solutions.- Conductivity of Concentrated Metal-AmmoniaSolutions in the Frequency Range 0–70 GHz.- Discussion.- Strange Magnetic Behavior and Phase Relations of Metal-Ammonia Compounds.- Discussion.- On Superconducting Metal-Ammonia Complexes.- Discussion.- Metallic Vapors.- Metal-Nonmetal Transition in Expanded Liquid Mercury.- General Discussion of Papers by HENSEL, and EVEN/JORTNER.- Metal-Nonmetal Transition and Exciton Screening.- Discussion.- Mobility Studies of Excess Electrons in Nonpolar Hydrocarbons.- Discussion.- Excitons in Liquids and the Energy of the Quasi-Free Electron State.- Discussion.- Electron Localization in Dense He Gas.- Discussion.- Excess Electron States in Dense Polar Vapors.- Discussion.- Optical Absorption Spectrum of the Solvated Electron in Ethers and in Binary Liquid Systems.- Discussion.- Radiolytic and Photolytic Formation of Stable eam? in Amide Solutions.- Kinetic Studies of Reactions Involving the Ammoniated Electron.- Comments on Electron Transfer Reactions.- Discussion.- “Spin Off” Solvated Electron Research.- Color Plates.