The phase equilibria of the systems a r e discussed:(i) n-butanol-acetic acid-water and n-heptane (ii) Water-acetic acid-benzene and carbon tetrachloride (iii) Water-methanol-p.cresol and methyl naphthalene have been studied and a correlating procedure has been developed that utilize5 binary and ternary experimental data to predict the composition of the quaternary equilibrium mixtures. Allowance is made for the different salting effects and the agreement between the experimental and predicted quaternary data is in all cases very good.