(134) 



</ 8 i|' 



dp 



the w-axis can he drawn to — == 0, and the point where — = 



lias minimum volume must lie in such a way, that the last point 



lies between the two tirst mentioned. If the line = is restricted 



das 1 



dp J 2 t}j 



to smaller volumes than — = 0, then = must also lie at smal- 



d.v d.v' 



ler x than the point where 



has the smallest volume and the 



Fig. 24o 



Fig. 246 



Fig. 24c 



reverse; this has been represented in tig. 24c/, fig. 24/; and fig. 24c, 



but has not always been kept in view in preceding sehematical 



figures, which were plotted for the representation of other particularities. 



After these remarks we may examine more in details what happens 



when ( — 1 = and — = intersect, and the temperature is raised. 

 \dx) d.v* 



With rise of T 



da? 



contracts to the point in which this curve 



must disappear. Also the curve — =0 contracts. If the point in which 



dx 



I'll' dp 



must disappear, lies at smaller volume than — = 0, then 



,1, 



,/-> 



with contraction of — =0 the right-hand point where the latter curve is 

 directed y-axis, will have to pass through the minimum volume of 

 — =0. Even then there is still intersection, but with further contraction 



d.r 



the two curves will touch, and get detached. Above the temperature at 

 which they touch, the complicated course of the (/-lines has disappeared 

 in so far that no ry-lines occur any more which have split up into 

 two separate branches ; then we get a group of g-'ines as drawn in 



