AbstractData are reported for the evaporation of spheres of naphthalene into air, helium, carbon dioxide, and Freon‐12, and of liquid diethyl adipate into air at pressures from 0.1 to 3,000μ Hg and at Reynolds numbers from 0 to 1.37. By use of suitable values of the surface‐evaporation coefficient and the assumption of additivity of surface evaporation and diffusional resistances, the data are well correlated. The results lend semiquantitative support to the theory of sublimation of crystals developed by Stra