The Doctrine of Latent and Specific Heats. Second Reversal Theorem. Fundamental Theorem of Calorimetry

Abstract

Axiom II (Doctrine of Latent and Specific Heats).The heating Q of a given body in any process V, θ is determined as follows by means of functions Λ_Vand K_V, defined over D, continuous and having continuous partial derivatives there:

$$Q = \Lambda _V (V,\theta )\dot V + K_V (V,\theta )\dot \theta$$

(3.1)

at all times when $\dot V$and $\dot \theta$exist. Moreover,

$$K_V > 0.$$

(3.2)

Historical Comment. Studies of the history of thermodynamics have failed, generally, to notice that this axiom was accepted, if often only tacitly, by every early author of thermodynamic research. The earliest fairly clear statements of it seem to be those of Clausius (1850) and Kelvin (1851). The ideas it represents were distilled from the experiments on calorimetry in the late eighteenth century. See the book by D. McKie & N. de V. Heathcote, The Discovery of Specific and Latent Heats, London, Arnold, 1935.