We present measurements of the local composition about the fluorescence probes pyrene and benzo[ghi]perylene in binary liquid solvents. The probes provide information about the solvation of the solute on a microscopic scale. The advantage of the fluorescence probes is that they are relatively nonpolar and do not contain functional groups with which to form hydrogen bonds. Actual measurement of local compositions is important as the concept is the basis of a number of useful thermodynamic models. Thus, we compare the measured values with those predicted from both the nonrandom two-liquid (NRTL) equation and the Wilson equation. The standard recommended values of the nonrandomness factor in the NRTL equation generally underestimate the magnitude of the local compositions. Larger nonrandomness factors provide better descriptions of the microscopic environment. On the other hand, the Wilson equation overestimates the magnitude of the local compositions in all cases.