( 2?>C> ) 

 b 



8 7' 

 1 



27 7/. 



Tliis valiio for v lies betwoon od aiirl 2 />. 



As in tlio precedin.o' caso tlioro is no quostioii of a maximum 



value. 



27 . . , . 



?>". for T between — Tj. anrl 7) , the limiting value of r — v is 



eontained between h and 2^/3 &. Wiien the volume decreases, v' — v 

 begins to increase, till a certain maximum value is reached, which 

 amounts, however, at the utmost to 2.27 times the limiting value. 

 It decreases afterwards, reaches the value and ends with — b. 



4°. for values of T ^ Tj^ only those values of v have to be con- 

 sidered, which lie beyond the limits of coexisting gas- and liquid- 

 volumes, and v' — V loses even its theoretical signification for such 

 volumes for which the pressure on the theoretical isothermal is nc- 



27 

 gative. For T= — 7). the isothermal touches the ;>-axis at v = 2b. 



There the quantity v' — v is infinite, because if ;^=:0, ?;' is also infinite. 



But this does not mean at all that for the volumes which may be 



realized at that temperature, v' — v will increase to a high amount. 



27 

 Let us take e.g. Tz=z — TV. In order to find the highest value for 

 =•32 



v' — V, we have to determine the value of v for saturated vapour and 



to sul)stitutc that value of r in the formula 



V V =z 



Let — be taken equal to — , — and as at this temperature a' ^ ib 

 V 25 



we find 



4 



3 



25 



v' — V -^ b 



2 n2 ' 

 257 



so a value which is not much hio-her than the limiting value. If 



(-^J 



