Methane diffuses in water at 25°C 3/5 as fast as it does in carbon tetrachloride. Since diffusivity depends mainly upon temperature, viscosity of the solvent, and molecular cross section of the diffusant, and since viscosities of H 2 O and CCl 4 at 25°C are almost identical, one may infer that molecules of CH 4 in H 2 O are not imprisoned in “icebergs,” and are retarded only by hydrogen bonds, not by encounters with “ice-like” aggregates.