The Heat Capacities of Benzene, Methyl Alcohol and Glycerol at Very Low Temperatures

Abstract

The design and operation of a low temperature vacuum calorimeter which is internally cooled from 13° to 2°K is described. The principle employed is that of adiabatically expanding cooled helium gas from a small pressure chamber, located inside the calorimeter can. The heat capacities of crystalline benzene and methyl alcohol and crystalline and glassy glycerol have been measured down to 3°K. New values of the entropies of these substances at various temperatures have been calculated. Below 9°K the heat capacity of glassy glycerol is 100 percent larger than that of crystalline glycerol. The glassy form apparently has 4.64 units of entropy at the absolute zero.