The study of the properties of solutions has been one of the most important branches of physical chemistry since the seventeenth century. In spite of the enormous volume of work that has been done in this field, it is a fact that in only a very few simple cases can the experimental properties of the solutions be predicted from the theoretical considerations. In this thesis a study is made of binary solutions of which one of the components is water. Before the properties of mixtures are considered, it is necessary first to discuss the characteristics of pure liquids. Liquids have been classified:- (1) normal, which have low dielectric constants and conform to the number of rules concerning surface tensions, heats of vaporisation, etc., (2) abnormal, which have again abnormally high dielectric constants, surface tension and heats of vaporisation than would be expected on the basis of normal liquids. This has been explained by the fact that the molecules in liquids are non-polar and polar, i.e., the latter possess permanent electric dipoles while in the former the centres of the positive and negative charges coincide. Attempts have therefore been made from time to time to distinguish between these types of liquids.