An improved design of a liquid membrane diffusion column was developed which enabled the measurement of a concentration difference of surfactant between liquid membranes and the solutions used to form them. The previously proposed model for liquid membrane diffusion which assumed that the films were of the order of a few molecules thick was not consistent with the data observed using a specially designed diffusion column. A bimodal droplet distribution was measured for a typical emulsion, and the influence of the liquid constituent of the membrane on the permeation rate was investigated. No statistically significant difference in permeation rates was noted when different liquids were used to form the membranes.