The Gibbs surface elasticity was detd. in 0.001 Mag. hexadecyltrimethylammonium bromide (CTAB) with a Langmuir-Wilhelmy balance at 15 and 25 degrees C. At the start of surface compression, the elasticities were 5.6 and 2.6 mN/m, resp. The relative rate of surface tension re-equilibration, calcd. from the dynamic surface tension curves detd. by the max. bubble pressure (Kruss), was 1.26 and 1.73 l/s, resp. These data were consistent with the longer life-time of the CTAB soln. foams at 15 degrees C, explicable in terms of the Marangoni effect. Capillary flow was also demonstrated for the 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine monolayer acting as a phys. model of the lung surfactant. Marangoni effects were shown to affect the hydrodynamics and mass transfer in tech. and biomedical processes.