The coexistence curves L1 [Formula: see text] L2 of the following systems have been investigated: (1) aniline–hexane; (2) methanol–cyclohexane; (3) methanol – carbon bisulfide; (4) acetic anhydride – cyclohexane; (5) acetic anhydride – carbon bisulfide; (6) triethylamine–water. Instead of using the usual method of Alexejew, which has disadvantages stated in the text, we have preferred the direct analysis of equilibrium phases at constant temperature.