( 296 ) 



follows, because f/h^ and ^-- are equal to 0: 



'p\ f ö> ^ dl\. 



and from the relation : 



follows : 



ydvdTJ dv' ' 



And from this we find again now onlj" from thermodynamic 

 relations what we have derived already above. 



As we found, also by means of mere thermodynamics : 

 dp\ , ( (IT, 1 dpy. 



we may put without making use of the equation of state : 

 dT _ dT, fY \ dT, 1 dp,]' 



bv' 



The factor ^— may be reduced to a simple form, but for 



3IRT—- 



the determination of the value of this factor it is required to know 



MRT ^ b's ^ a , 



the equation of state. If we write fp =. -, and — - = — 2 — ,this 



^ V — b 01?' y' 



MRT 2a , MRT /^ db\ 2a 



MRT 2a ^ MRT / 



factor becomes equal to — "• — and as ; — 1 



(?; — by V {v — bj \ 



follows from ( ^ j =0, we get : 



bv 



MRT -_ 1 — — '•' '' 



Or" ov 



15 

 so with /= 7 and y. = — the value of this factor becomes equal 

 ^ 4 



49 

 to — -. Hence we have : 

 45 



dT dT, 49 ( dT,. 1 dp. 



Tdx, T,dx 45 ( T,dx 7 pydx 



dpx 

 If we introduce the quantity b instead of — — , we find: 



p,dx 



