A Taylor vortex column provides a large shear in the absence of form drag in contrast to other common mixing devices. In particular, the power per unit mass for a column is expressed in terms of a torque coefficient and compared with similar expressions for both, a stirred tank (power number) and a static mixer (friction factor). Results of computational fluid dynamic computations provide a picture of essential features of the flowfield. Moreover, experiments with a prototype Taylor column are presented for the continuous liquid-liquid extraction of benzoic acid from toluene to water. Arguments are presented for the observed increase in stage efficiency with larger volume fractions of dispersed toluene.