Turbidity in the one-phase region and the isobaric heat capacity per unit volume in both one-phase and two-phase regions for the critical solutions of {benzonitrile + n-alkane} were measured, from which the values of the system-dependent critical amplitudes for the correlation length, the osmotic compressibility, the heat capacity and the correction-to-scaling term of the heat capacity were deduced. The previously reported data of the coexistence curves for {benzonitrile + n-alkane} were also reanalyzed with the crossover model to obtain the crossover parameters. Subsequently, these results together with the values of the critical amplitude related to the coexistence curve reported previously were used to calculate some universal critical amplitude ratios, which showed reasonable agreement with the theoretical predictions. (C) 2013 Elsevier Ltd. All rights reserved.