The present study deals with the mutual miscibility of n-butyl alcohol and wrater, particularly in the presence of added salts. The effect of such substances on the critical solution temperature was investigated by Timmermans (25) for several pairs of liquids, and an extensive study of the systems salts-phenolwater has been made by Patterson and his coworkers (18,19,20,21). They conclude that the elevation of the binary critical solution temperature is the sum of two values, depending on the cation and the anion. The respective ions, when arranged in the order of their effect, form series almost identical with the Hofmeister series. Taylor (24) has made a similar study, and Jacobs (11) has