( 240 ) 



In this figure v and v' — v have been taken as axes. The origin 

 is in point 0. At T:=co v' — v is equal to — b for all values of v. 

 In the figure this has been represented by a line parallel to the 

 ïj-axis. If the variability of b with the volume could also be taken 

 into account, this straight line would naturally have to be changed 

 into a curve, which approaches asymptotically the position given 

 here when the volume is large and which has come sensibly closer 

 to the v-axis at the smallest volume possible. But then every curve 

 had to be modified, specially in the region of the small volumes. 



Under an infinite pressure the value of v' — v is equal to — b at 

 all temperatures. Hence all curves pass through the sxme point. 

 According as the temperature falls the curves begin higher at 



27 



?■ = 00 . The curves drawn are those for 2' = — 7), (the temperature 



at which a substance obeys the law of Boyle, if the volume is 



27 ... . , 



infinite); for 7= — ?),• (the limiting temperature at which v — v 



begins to show a maximum value), for 7':=^/s 71- and T =z Tk. 



The maxima lie on an equilateral hyperbola, which has v ■=z2h 

 and v' — V = 6 as asymptotes. 



"When the volume is rather large, the different curves do not 

 differ sensibly from straight lines parallel to the r-axis. 



