A detailed experimental investigation was made of the specific heat of an Hg 2 Cl 2 single crystal in a wide range of temperatures, including its phase transition point. The temperature dependence of the anomalous part of the specific heat associated with the phase transition was determined accurately in the range T < T c and the critical power exponent α was found. The results obtained suggest that the phase transition in Hg 2 Cl 2 crystals could be close to the triple point