The transfer of molecular excitation energy from solvent to solute in liquid organic solutions under ultra-violet excitation has been studied as a function of different parameters such as solute concentration, exciting wavelength and dilution of absorbing solvent with a second transparent solvent. By measuring the fluorescent efficiencies of the solutions at different exciting wavelengths the intrinsic transfer efficiency can be found. It is found that the transfer probability is accurately proportional to the solute concentration, and is independent of exciting wavelength in the region in which the solvent absorbs appreciably. An investigation of the quenching of the transfer process by carbon tetrachloride shows that an average time of about 10^-9 second must elapse before the solvent excitation energy is transferred to the solute at optimum solute concentrations. It is shown that in diluted systems the solvent excitation energy is not exchanged between different solvent molecules before transfer. In undiluted systems there is evidence for a short range interaction between the solvent molecules leading to a relatively weak transfer of excitation energy through neighbouring solvent molecules. It is shown that the processes of natural solvent fluorescence and solvent-solute transfer are not competing processes which can take place from the same molecular state.