hydrocarbon from water to its pure liquid phase. Then water is defined by its a, y, and a, and in our opinion the relative influence of these three parameters on the transfer has not been clearly assessed.

Publication costs assisted by the Commissariat a' I'energie atomiqueThe solubility of helium and methane in aqueous BmNBr solutions has been determined at 25 and 35°. The salting-out constant and the enthalpy of solution have been calculated according to the scaled-particle theory neglecting the influence of dispersion forces, and these values are compared to experimental values. For helium the fit between the calculated and experimental dependence of enthalpy and salting-out constant on salt concentrations is good. For other solutes the agreement decreases as the polarizability of the solute is increased.

Publication costs assisted by Commissariat á I'Energie AtomiqueIn the present article, we report the results of nmr measurements of the chemical shift of the water proton in solutions of methyl, ethyl, n-propyl, n-butyl, and tert-butyl alcohol at various temperatures and concentrations. At low temperature the downfield shift of the water proton is consistent with an increase in water structure promotion by the solutes. At high temperatures, the upfield shift is consistent with a weakening of the water structure by the solutes. These results are also qualitatively consistent with what may be expected of the influence of hard-sphere molecular solutes on the water structure. The enthalpy of transfer of some alcohols from light to heavy water at 51°is given, but the classical interpretation of this type of measurements is questioned. Finally the enthalpy of transfer of t-BuOH from H2O to t-BuOH aqueous solutions is also given and discussed according to current interpretations based on the overlap of hydration spheres around a hydrophobic solute. These interpretations are also questioned. Discussion 1. Nmr Measurements. Using an internal standard, we have found that at 0 and 40°the molal chemical shift caused by f-BuOH is respectively 2.5 and 0.8 Hz downfield. Corresponding numbers found in ref 2 are respectively 3.0 and 1.0 Hz using an external standard.

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