We report new results of nucleation measurements carried out in our laboratory at a variety of constant total pressures for 1-propanol vapor with nitrogen, helium, and hydrogen as background gases and for 1-butanol vapor with nitrogen and hydrogen as background gases. In addition, we report new results of nucleation experiments carried out at a variety of constant temperatures for 1-butanol with helium and hydrogen as background gases. The 1-butanol constant temperature results compare favorably with the results of the 1-butanol constant total pressure experiments, and the constant total pressure data for 1-propanol obtained in this investigaton compare favorably with constant temperature results obtained from 1-propanol experiments described in the literature. The results of this investigation (continue to) suggest a significant role of the background gas in the nucleation process. Our constant pressure and constant temperature experiments reported here give new results that reinforce our earlier observations that as the amount of background gas is increased, the rate of nucleation decreases. We continue to find that the magnitude of this effect becomes greater as the molecular weight of the condensable increases. Similarly, for all of the alcohols we have investigated, this effect becomes greater as the formula weight of the background gas increases, and the slope of the dependence of the critical supersaturation on total pressure increases as the temperature decreases.