T HE general influence of dilution on a hydrogen bonding substance is well known to consist of a drastic decrease in intensity of the absorption band connected with the stretching vibration of the bonded group, and the simultaneous appearance and increase in intensity of a band corresponding to the same vibration in the unbonded molecule.l The solvents chosen are always nonpolar, and considered to be inert, but specific differences must, of course, exist between them. Few studies have been made of these specific interactions,2 and these were made under conditions where interaction occurs only between solute and solvent molecules, but not between solute molecules mutually. In inert solvents this requires very low concentrations. At higher concentrations both associated and free molecules are present, and the intensity of the monomer band can be taken as a quantitative measure for the amount of monomers, using the intensity in the very dilute solution as a standard.! During the course of an investigation of a series of alcohols it became apparent that the solvent-solute interaction cannot be entirely neglected. In order to establish the extent of such specific effects a semiquantitative study has been made. As a representative alcohol propanol-1 was chosen. Spectra of the OH stretching frequency have been obtained at various concentrations in three nonpolar and three polar solvents, using a Perkin-Elmer Model 21 spectrometer equipped with a rocksalt prism, and a spectrometer designed and built in this laboratory, which was equipped with a LiF prism. The slight absorption of