HEATS OF TRANSPORT OF GASES .I.

Experiments on thermoosmosis of nitrogen and carbon dioxide through porous unglazed porcelain have been described. Isothermal permeability and thermoosmotic pressure have been measured. Results have been interpreted from the viewpoint of irreversible thermodynamics and the kinetic theory of gases. A linear phenomenological equation for mass transport is found to be valid up to temperature differences of the order of 130°. Heat of transport is a slowly varying function of mean temperature but it depends significantly on mean pressure. The dependence of heat of transport on mean free path is discussed.