Now 



and 



(275) 







or tcaking into consideration ^-r 3-7 = 3^ and ^— = 



(Ü?i r 2 



and 



öy \bx^v ) ö^'ij^ dicdy d.t-öy" 



«W r 1- 



dy^ ö.r V ö.?? dy ^ /ö^V ^ V ö^^dy y ^x dy^ * 



a/ ö> öy ö> 



By equating — ^-^ and ^ -^— we find : 



ÜVOXÜV QX OV^ 



d> ,. ö^ , d> /d>Y , d^ ö> 



r-^ hm. — 2 ——- = — — - hm. 1 ~. 



öxdv d> dxdv' \dxdvj fd'^Y dxdv^ 



d'ip 



dx^ 

 For normal substances the limiting value of -r is known 



From <f> = MRr{{l—.v)l{l-.c) + d.v]— fpdii follows: 



\OxJv 1— A' J Ox 



(p)^MRT-J r^.y 



Vd.t-V x{l-x) J dx' 



/d>\ _ __ MRT(l—2x) rd'p 



[d^J - ~ x\\-xy ~J d? "^^ 



d'xp 



a7 1 



for .V = we get . = — 





19* 



