Fig. 3. Plots of the overall free energy of solvation into (A ) benzene and (B ) ethyl methyl sulfide for six anesthetic and two nonanesthetic molecules (from table 2) as a function of molecular volume. Linear regression least squares fits were generated using KaleidaGraph version 3.0.5 (Abelbeck Software, Reading, PA, 1994). The correlation coefficients (r) are (A ) 0.8933 and (B ) 0.8920. The nonanesthetic data are the filled circles.