A new method,based on electrical conductivity,for the study of demulsification has been developed and applied to W/O emulsions,using oleic acid-ammonium oleate as emulsifying agent.From the variation of conductivity with time the rate of coagulation of the water droplets and the activation energy of the process have been calculated.It was concluded that the rate of coagulation is determined primarily by the coalescence of the water droplets and is kinetically of first order,the most important factor being the breakdown of the surface film.The effect of the amount of emulsifying agent on the activation energy has been pointed out and the result of Wellman and Tartar on the influence of temperature on stability has been discussed in light of this work.