Abstract
(First paragraph) The treatment of thermodynamics may be classified from two different points of view: the thermodynamic and the statistical mechanical. In the thermodynamic treatment the system as a whole is described by its macroscopic properties, whereas in the statistical treatment the system is constituted from an assembly of large numbers of individual molecules. In common with other branches of science, the thermodynamic treatment is based more directly on human experience, whereas, in the latter treatment, use is made of statistical principles, as well as quantum mechanics. In this thesis the thermodynamic treatment will be primarily considered.