The total vapour pressure of {xXe + (1 - x)B(CH3)(3)}(l) has been measured at T = 161.39 K and T = 182.33 K (the triple points of xenon and nitrous oxide, respectively). The excess molar Gibbs energy G(m)(E) has been calculated, as a function of composition, from the vapour pressure data. The molar volumes of the mixtures were also measured at T = 182.33 K, and the corresponding excess molar volumes V-m(E) calculated. The results were interpreted using the Deiters equation of state DEOS, and Monte Carlo simulation.