Abstract
With isopentane as the dilatometric liquid, CH3OD was examined between 120 °K. and the melting point. There is evidence of two transitions within the solid: one, in the vicinity of 158 °K., appears to be a gradual transition, the other, at 163 °K., a first-order one. The corresponding molar volume changes are 0.04 and 0.43 ml. A further change of volume of 2.67 ml./mole occurs at the melting point. These results are compared with recent dilatometric results for CH3OH and discussed with reference to the available calorimetric data. The molar volume of CH3OD is slightly greater than that of CH3OH in both liquid and solid forms.