Thermodynamic Fluctuations near a Critical Point in Binary Mixtures

In contrast to a rather common statement, we show that at a liquid-liquid critical point there are very large density fluctuations. A general property of the correlation functions of local dynamical variables is proposed on the basis of the behavior of various thermodynamic derivatives near a critical point in binary mixtures. Our analysis applies to the general case. Possible isolated points such as an azeotropic critical point are not considered.