III. Determinations of the heat capacity and heat of fusion of some substances to test the validity of person's absolute zero

Abstract

The relations existing between the heat of fusion of a substance and its heat capacity in the liquid and solid condition were demonstrated by Person, in 1847 (‘Ann. Chim. Phys.’ (3), vol. 21, p. 315). He showed that the heat of fusion must diminish as the temperature is lowered, the decrease per degree being equal to the difference between the heat capacities of the liquid and solid, and that, therefore, there must be a certain temperature at which the heat of fusion will be nil, this temperature being given by t - l /C- c , in which t , is the melting point of the substance, l its heat of fusion at t , and C and c its heat capacity in the liquid and solid conditions respectively.