o GJ

Liquid mixtures which exhibit a lower critical solution temperature are of two types. The first type contains liquid pairs in which there is a great difference in molecular size between the two components'. The second, and by far the larger, group contains those in which interaction between the components occurs by means of a hydrogen bond. Triethylamine + water falls into the second group. The system triethylamine + water has been very widely studied, the earliest work having been done in 1884. Since then a number of determina-tions of the phase diagram has been made, but later work has only been distinguished by the large number ofdifferent results that has been obtained. In Figure 1 several earlier diagrams are illustrated. (J