Preface. Part I - Theory. Structure and dynamics of clusters: an introduction (R.S. Berry). Structure and dynamics of clusters: phase equilibrium and phase changes (R.S. Berry). Size effects in clusters (J. Jortner et al). A structural approach to the analysis of clusters dynamics (F.G. Amar). Spectra, phase transitions and ``dynamical isomerizations'' of mixed van der Waals clusters (R.J. Leroy). The Car-Parrinello method and its application to microclusters (W. Andreoni). Simulation of metallic and impure van der Waals clusters (R. Kawai et al). Clusters of quantum liquids (S. Stringari). Fragmentation of clusters (X. Campi). Part II - Spectroscopy and Photodissociation. Infrared spectroscopy of large clusters (R.O. Watts). Infrared spectroscopy in and on argon clusters: surface and matrix spectroscopy in the gas phase (D.J. Levandier, M. Mengel and G. Scoles). Spectroscopy, reactivity and photodynamics of size-selected metal clusters (G. Delacretaz et al). Size-dependent properties in small metal and semiconductor clusters (M. Moscovits). Structures of metal clusters (W.D. Knight). Interaction between visible laser light and van der Waals clusters formed in free jet expansions: Raman induced photodissociation (T.D. Mark et al). Spectroscopy and dynamics of ``van der Waals'' cluster ions (D. Ray, N.E. Levinger and W.C. Lineberger). Photodetachment spectroscopy of negative cluster ions (S.T. Arnold et al). Excitation of free metal clusters (C. Brechignac and Ph. Cahuzac). Part III - Mass Spectroscopy Scattering and Chemical Properties. Electron diffraction studies of clusters produced in a free jet expansion (G. Torchet et al). Cluster properties from scattering experiments with atoms (U. Buch). Crossed molecular beam experiments on nitric oxide clusters (L. Beneventi et al). Helium clusters (J.P. Toennies). Solvated electron clusters (H. Haberland). Chemistry of carbon and silicon clusters (M.L. Mandich). Experimental studies of the chemistry of metal clusters (E.K. Parks and S.J. Riley). The unimolecular fragmentation of ion clusters (A.J. Stace). Molecular clusters isolated from aqueous solutions by adiabatic expansion of liquid jets: a new approach for molecular association in solutions (N. Nishi and K. Yamamoto).