1)According to the formula of Massay and Mohr, the viscosity cross-section has been calculated quantum-mechanically in more details than they did, using the rigid elastic sphere model. 2) The viscosity coefficients of neon and helium have been calculated over wide temperature ranges, and it has been found that the concordance between theory and experiment is yet insufficient, though it is better than the result of the classical method. 3) The agreement has been improved, if the “Sutherland term” is introduced in the formula to take the intermolecular potential in consideration. 4) The criticism of Uehling to Massay and Mohr’s result has been found rather inappropriate, so far as the similar collision is concerned.
1) According to the conclusion of the previous paper, the “Sutherland constant” in the viscosity coefficient for various substances has been calculated quantum-mechanically by a simple procedure. 2) The Sutherland constant C0 thus calculated has been found to obey Rankin’s and Vogel’s rules even in the substances of low molecular weight. 3) The disagreement in the Debye’s formula between electric moment and Sutherland constant has been shown to disappear if C0 was used instead of the classically determined Sutherland constant.