Structure in Surfaces of Liquids

MR. HATSCHEK, in his interesting article in NATURE of June 11, p. 857, has shown that colloidal solutions and even the simplest suspensions of solid particles in liquids exhibit a property which is absent from all true liquids; namely, residual rigidity, or at least a coefficient of viscosity that depends upon tho rate of shear. He has advanced no explanation of this remarkable result, which would, however, appear to be just one manifestation of a general property of all surfaces involving liquids.