(BS 
dp 
dv 
point of intersection branches of isobars with negative value of the 
—( is found on the right below this temperature, round which 
27 
pressure pass as closed curves. For ab of the minimum critical tem- 
perature the loop-isobar will hold for the pressure 0, as we saw 
d 
above. So it reaches the vapour branch of at only at infinity 
Vv 
(fig, 16). For still lower temperature also the loop-isobar in the case 
Fig. 16. 
of vaN per Waats is no longer closed round the point of intersection 
d d 
of ef with the vapour branch of Ze but round the third 
v v 
point of intersection. Of course closed rings continue to run round 
En 
/ = ~ 
/ os 
rat 
/ eae 
—| 9 ms 
Sng 
- © 
tape) EREN - 
+ Eke XN 
; kg Den ms 
“ 5 
La ~ 
Fig. 17. 
