The project examines the formation of precritical molecular clusters in metastable supersaturated aqueous solutions of glycine, NaCl, KCl, and NH4Cl. These molecular clusters affect solution properties such as viscosity and diffusivity and plays an important role in nucleation and crystal growth. A Spherical Void Electrodynamic Levitator is used to obtain highly supersaturated droplets. The size distribution of clusters in these droplets is measured directly by quasielastic light scattering. The data are used to resolve certain important outstanding problem in nucleation theory, involving cluster size and evolution. The results of this interdisciplinary project, by one chemical engineer and one physicist, are important for better understanding and designing crystallization process for separation and purification of many industrial and pharmaceutical products.