[ 115 ] 
V. On the Kinetic Theory of a Gas. Part II.—A Composite Monatomic Gas : 
Diffusion , Viscosity , and Thermal Conduction. 
By S. Chapman, M.A., D.Sc., Fellow and Lecturer of Trinity College, Cambridge. 
Communicated by Sir Joseph Larmor, F.R.S. 
Received May 19,—Read June 29, 1916. 
Contents. 
Page. 
§ 1. Analysis of the dynamical state of a composite gas.118 
§ 2 The equation of transfer of molecular properties.123 
§3. The velocity-distribution function /(u, v, w). . . 128 
§ 4. Completion of the equations of transfer.131 
§ 5. The symbolic solution for the coefficients in /(u, v, w).136 
§ 6. The complete solution for Maxwellian molecules.144 
§ 7. The general solution when : m 2 is very large.146 
§8. The general solution for the case of similar molecules . ... 149 
§ 9. First and second approximations in the general case.151 
§10. The equation of diffusion.157 
§11. The equation of viscosity.159 
§12. The equation of energy. .160 
§13. The coefficient of diffusion Di 2 .165 
§14. The coefficient of thermal diffusion.181 
§15. The coefficient of pressure diffusion.186 
§16. The steady state without diffusion. 186 
§17. The coefficient of viscosity.189 
§18. The coefficient of thermal conduction.190 
§19. The specific energy of diffusion.191 
§ 20. Appendix on the inequality of temperature between the component gases.192 
Introduction.* 
The present memoir was originally intended to deal only with the theory of diffusion, 
which still remains its chief subject. During the course of the work, however, it 
became clear that the theory of viscosity and thermal conduction could also be 
incorporated by a slight extension of the analysis. This has been done, and the 
paper now affords an account of all these three ordinary ” mean-free-path phenomena 
of a composite gas. 
The treatment of viscosity and conduction is brief, partly because the theory 
for a composite gas is so much more complex and less important than that for 
* See Note F, p. 197. 
VOL. CCXVII.-A 553. S [Published June 25, 1917. 
