468 



ME. S. CHAPMAN ON THE KINETIC THEORY OF A GAS 



my knowledge, but the value 100 (intermediate between the values of C u for argon 

 and helium) is near enough for our purpose, as the constant does not have much 

 weight in the formula. 



From the equations (41) it is an easy matter to calculate the constants E, F, G, 

 Ej, Fj, Gj ; we find the following values* for the three special kinds of molecules 

 considered : 



Rigid spheres 



E = 6'66, 

 E! = 3-93 xlO 4 , 



Maxwellian molecules 



E = 4-10, 

 Ej = 2'42 xlO 4 , 



Attracting spheres 



E = 5'38, 

 Ej = 3'17 xlO 4 , 



We have written Ej and G, 

 thus becomes 



F = 2073, 

 Fj = 376 xlO 4 , 



F = 17-56, 

 F! = 2'65 x 10 4 , 



G = 10'GO, 

 G! = 0704 xlO 4 . 



G = 10-65, 



0706 xlO 4 . 



F = 19'0, 

 F! = 313 xlO 4 , 





G = 10-56, 

 G! = 0700 xlO 4 . 



in place of EW//U and Gw'/fj.' respectively. Our formula 

 Ep 2 +~Fpp' + Gp' 2 



where (G V ) 12 is given by equation (3 9 A). The following table gives the values of p 

 and p' and the observed values of S 12 ,t from WACHSMUTH'S paper, together with & 13 

 calculated according to the above three hypotheses : 



THERMAL Conductivity of Mixtures of Argon and Helium. 



h These and nearly all the other calculations in Part III. have been performed with a slide rule, which 

 is accurate enough for the purpose. 



t S>, 2 was determined at two temperatures; we are, of course, using the value reduced to C., as 

 given by WACHSMUTH. 



