CONSTITUTED OF SPHERICALLY SYMMETRICAL MOLECULES. 451 



In these last expressions w and w' are the specific gravities of the two component 

 gases referred to a standard gas whose density at the pressure and temperature of 

 the compound gas here considered is po ; and G is given by 



(38) G 



Since the partial pressures of the component gases are directly proportional to v, v 



v ,_ v'\ 

 OT P== 2h' P := 2V' W 



Ptl+P'*! = ~ j 



Zh+k ^W+ IiE KJ+ 1 1 ^' + Ui+i !2^p. 



At\ UT/ L IVW (jr/mfjL } (i, \ W 1 



Similarly we may show that Pzy+p'zy is the same multiple of F. Hence, recalling 

 the denotation of E and F, and comparing the said equations with the equations of 

 pressure in a medium whose coefficient of viscosity is M> as in 7, we obtain the 

 following equation : 



/oq\ 



(89) 



11. The Coefficient of Theivnal Conductivity of a Compound Gas* 



From equations (26) and (29) we see that &u(u a +v*+w i ) a and Aw' (tt"+v' a +/*) 

 can be expressed as in the following equations : 



Aw 



where A, B, C, D are written for convenience in place of some rather long expressions 

 which can easily be written down from the equations cited. 



Remembering the values of a^ and a\ as found in 4, and substituting from 

 equation (10) for A?t(w 2 +tx'+w a ) , the last equations may be written 



2= ,(A U(U 2 +V 3 +W a ) +BU / (U /a +V"+W") ), 



ox 



5v > q > = j (c u(u a +v+w 2 ) +D uxu^ 



* Added October, 1911. See the footnote to p. 444. 

 3 M 2 



