some New Equations derived therefrom. 25 



The volume Y would contain of the latter 



Y 



N : = -y— 7 N molecules, . . . . (1) 



having a volume 



£=VT^ < 2) 



The specific density referred to in the introduction is 



Nt V 

 "=N = VT&' (3) 



and expresses the density of an actual gas with regard to a 

 perfect gas at the same temperature and pressure II. 

 For the perfect gas, 



11 v ' 



and for the actual gas at the same volume Y, 



U =T^W (4) 



As stated above, we must of course find 

 Y 

 y.B.T _ Y + ?> ,R,T _R.T 



Y±b'° 

 On the other hand we had 



P l5 the inward pressure, being inversely proportional to 



the density, i. e. to v 7 , is equal to ^ — j-^ if a is the 



constant at Y = l ; and instead of van der Waals' equation, 

 we find 



p +(v+^ = --r (A) 



In this equation 6, the volume of N molecules, is naturally 

 constant. The equation expresses that at the density^—— 

 and the volume Y, an actual gas "exerts the same pressure II 

 as a perfect gas at the density ^ and the same temperature. 



