Many properties of liquids and solids are dependent upon weak chemical bonds. Scientists have studied these intermolecular forces and their effect on the melting of solids and the evaporation of liquids. Using data which describe interaction potentials, one is able to predict with reasonable accuracy such properties as surface tension, interfacial tension, wetting of solids by liquids, compatibility of liquids, and the solubility of organic compounds. This manual demonstrates a practical method of estimating such properties for a number of organic liquids. Solubility parameters are given for selected solvents. -- AATA