The upper demixing critical point in carbon disulfide + nitromethane bounded by a crown glass surface which is expected to preferentially adsorb nitromethane has been studied. The $\sigma$-polarized reflectivity of the liquid/glass interface rises sharply with decreasing temperature above the bulk critical temperature. This effect cannot be explained as a purely bulk phenomenon, but agrees well with an approximate version of the critical wall-layer theory of de Gennes and Fisher.

• Received 29 October 1981

DOI:https://doi.org/10.1103/PhysRevLett.48.763