In this investigation a survey of the effectiveness of surface-active agents for the removal of heavy oils and tars from intact and from injured skin has been carried out. At the present time, a large number of surface-active agents are commercially available. These many compounds and mixtures have in common the power to modify the properties of surfaces but vary widely in specific modes of surface activity, such as wetting power, emulsifying power, and dispersing, penetrating and foaming action, not only with respect to any specific system of surfaces but also from one system to another. If the living skin is considered a component of such a system of surfaces, the pertinent powers of surface-active agents may in general be taken to vary between wetting power, on the one hand, and emulsifying power, on the other, although these do not necessarily oppose each other. The former is a measure of