( 196 ) 



Fig. 27. 

 of this line; the downmost is the hidden plaitpoint lying between 

 E and F. The place of the points E and F has been arbitrarily 

 chosen, so that it may also be possible that E must lie more to the 

 right than 7V, . At the value of To , the splitting temperature, 2 new 

 points appear. At Tp a couple of heterogeneons plaitpoints unite. 

 At Tq the detached longitudinal plait would disappear. Between 

 Tc and Tj) there are two plaitpoints for the detached plait. The 

 three phase pressure runs between G and L, the extremity L having 

 been chosen such that (he point 1) (splitting point) lies below the 

 three phase triangle, and can, therefore, not be observed. Hence only 

 the following 3 parts can be realized by means of the experiment: 

 1. H t G, 2. H,. ACL, 3. GL. And now, if the hypothesis that the 

 plait is closed on the side of the limiting volumes, should be incorrect, 

 we have only to open the upper part at A and C, and to make 

 the open branches run asymptotically towards infinitely high. So 

 this plaitpoint line is essentially the same as that with the double 

 point which I have drawn. Only one of the branches, i.e. the left 

 branch, has in addition got a maximum and a minimum pressure, 

 and a maximum and a minimum temperature. If we drew the T,x- 

 projection, there would be 2 maxima and two minima — also in 

 the p,.r-projeetion. But the v,.z-projection remains simple. If the plait 

 is closed at the limiting volumes, there is a minimum volume, in 



') In this figure the shape of the plaitpoint line has been drawn when really 



(Til; (fit» . . . 



the spinodal line could run between -— - = and — — - = 0. Further investigation 



do* de* 



will have to decide whether or no this complication can occur. If it occurs, the 



righthand side of the plait (transverse plait) will be much narrower, then when 



this complication is not met with. In the latter case the righthand part of the 



plait is a complex plait. 



