CORRESPONDING STATES 

 we obtain 



or 



In testing this so-called reduced characteristic equation 

 by the facts, it will appear that it does not represent the 

 behaviour of a particular substance 1 , but that it is very 

 suited to bring out the corresponding character of different 

 bodies. 



The first point will be plain on calculating 



=F 



7 



from the data for the best investigated substance fluor- 

 benzene. 



The values of F which should be constantly 8 vary 

 greatly, being too low for liquid, too high for vapour. 



Still on comparing substance with substance striking 

 relations appear, dependent on the fact that a reduced 

 characteristic equation, such as that under consideration, 

 represents the behaviour of all substances by a single 

 isothermal for each value of y. Referred to the volume 

 that means that at equal fractions of the critical tempera- 

 tures, the liquid volumes are equal fractions, and the vapour 



1 Riecke, Gott. Nachr. 1894. 



