Revised thermodynamic relations for λ transitions in mixtures. III. The saturated vapour of solutions of 3He in liquid 4He below their λ temperatures

For pt. II see ibid., vol.5, 1015 (1972). On the basis of the discussion in part I of the possibility of obtaining Pippard's relations involving the dependence of a lambda temperature on the composition of mixtures, together with standard relations for liquid- vapour equilibria generally, comparisons are made between the behaviour of the specific heat of solutions of 3He in liquid 4He and (a) the change in the composition of the saturated vapour as the lambda temperature is approached, and (b) the change in the slope of the vapour pressure curve as the lambda temperature is approached.