We have measured homogeneous nucleation rates of n-pentanol droplets in argon using the nucleation pulse chamber recently described. The nucleation rates J were measured as functions of activity a at constant temperatures in steps of about 2.5 K for 241.8 < T/K < 271.0. The experimental data were compared with the predictions of the so-called self-consistent classical nucleation theory containing an additional exp(theta)/a factor. Smaller systematic deviations of the predictions of the theory from the experimental onset activities were observed than previously for other systems. Using a simple, alternative derivation of the so-called nucleation theorem we, furthermore, determined the average size of the critical cluster (n*) from the slopes of the isothermal J-a curves. We found that the self-consistent classical nucleation theory systematically overestimates the experimental n*’s.