The use of partitionable solutes, e.g., aliphatic alcohols, to enhance the recovery of trapped oil in reservoir rock, has been simulated using a ballotini-packed column initially flooded with kerosene, and subsequently lowered to an irreducible value by a water drive. Introduction of a "slug" of an alcohol effected an increased recovery, with n-propanol and sec-butanol giving the highest yields. Previous workers attributed such increased recovery to the formation of a "soluble front", in which both oil and connate water are completely dissolved. However, we obtained similar recoveries using slugs with initial compositions lying on the miscibility boundary, which could not form soluble fronts. It was therefore concluded that Marangoni-induced oscillation of the trapped drops is the more likely explanation of the enhanced recovery.