During recent years an increased interest has been displayed in the phenomena of gas conduction, particularly in their application to the observation of molecular changes and chemical dissociations. While relative measurements usually suffice for these purpose, there have also been carefully planned researches on the absolute thermal conductivities of gases, the results of which are of value in the development of the kinetic theory. A comprehensive account of the methods which have been employed in the past for the measurement of the thermal conductivity of gases is given in a recent paper by Trautz and Zündel, who include also a table of the available data to 1931 for air, hydrogen, and carbon dioxide. The lack of agreement between the values obtained by different workers shown in this table can be explained by the smallness of the quantity measured, and by the difficulty of eliminating the heat transfers by convection and by radiation, one or both of which are always present.
Kinetic theory of dense gases. The calculation of the viscosity and thermal conductivity virial coefficients