﻿GO Prof. J. H. Jeans on the H-Theorem and 



Prof. Lorentz. Lee us join a piece of real and a piece of 

 ideal matter, so as to form a closed circuit. Let one of the 

 junctions, A, be a perfect conductor of heat devoid of 

 radiating power, while each face of the other junction B is 

 a perfect radiator, devoid of conducting power. Let all the 

 rest of the surfaces of both R and I be supposed impervious 

 to energy. 



B 



If junction A is thrown out of action the bodies R, I will as 

 before assume different temperatures. If junction B is thrown 

 out of action the temperatures will equalise by conduction of 

 heat across A. If both junctions are in operation at once, 

 we shall get a continuous flow of energy round the circuit in 

 the direction I ARB, and a continuous rise of temperature 

 as we pass through I from B to A, or through R from A to B. 



These difficulties do not cast suspicion on the validity of 

 the second form of the theory of radiation, which begins 

 by presupposing a flow, rather than equilibrium, of energy, 

 but to the present writer they seem fatal to the thermo- 

 dynamical theory. 



Princeton, N.J., 

 April 24. 



VII. The H-Theorem and the Dynamical Theory of Gases. 

 By J. H. Jeans, M.A., F.R.S., Professor of Applied 

 Mathematics in Princeton University *. 



N the Phil. Mag. for April (pp. 455-465), Mr. Burbury 

 again discusses my work on the Theory of Gases. While 

 grateful for parts of his discussion which seem to be sym- 

 pathetic and appreciative, I recognize that on the main 

 question at issue Mr. Burbury is still inclined to disagree 

 in toto with my views. 



* Communicated by the Author. 



i 



