A thin film of the organic phase (kerosene) is allowed to rise through water between two vertical Teflon wires (diameter 0.79 mm) spaced 8 mm apart, with Teflon cross-pieces provided at intervals. The measured holdup exceeds prediction by a simple hydrodynamic model, due to a meniscus effect, but the model does provide a basis for correlation. The efficiency of mass transfer of acetic acid from the kerosene to water in this arrangement has been measured. The observed mass transfer coefficients generally fall below prediction by the semi-infinite penetration theory, except at high kerosene flow rates of 1.5-2 mL/s where intense rippling of the film is observed. A multistage countercurrent contractor using this principle is being developed.