( 11)9 ) 



the p, ^-projection has been drawn. At T= T\, which is lower 

 than TV, and 7j- s , the detaching takes place, and there is an 

 homogeneous double point. At 7 1 = T- there is an heterogeneous 

 double point, and at Td again an homogeneous double point. If we 

 suppose the longitudinal plait to be open towards v = b, po must 

 be thought infinitely large, and the upper part of this second branch 

 disappears. Without doubt the three phase pressure line, which 

 terminates in E, will have its other extremity, i. e. its initial point, 

 at T=0. 



We should have a very simple and remarkable case of a closed 

 curve for the second branch of the plaitpoint line if the lowest 

 temperature at which an heterogeneous double point is formed, lies 

 little below the temperature at which this double point vanished 

 again — and this temperature lies below T^ and J\. Then also 

 the temperature at which again an heterogeneous double point exists, 



Fig. 30. 



will lie only little higher than the first. Fig. 30 gives then again 

 the p, 1 -projection for such a ca a e. There can then be a phree phase 

 pressure indicated by a dotted line. Then the liquid begins to split 

 up into two phases at a temperature lying much below T Xi and T Xi , 

 becoming homogeneous again at somewhat higher temperature — at 

 least if the value of x has been chosen between that belonging to 

 the extremities of the three phase pressure. In the v,.r-projection we 

 have then a small closed figure with maximum and minimum volume. 



So many different shapes of plaitpoint lines, however, may be 

 deemed possible, that they would require a special study. If they 

 are found by the experiment, I expect that the rules given in these 

 contributions, will prove sufficient to render them intelligible. 



However, I intend shortly to indicate the circumstances in which 

 the forms discussed are met with, more fully by means of some 

 mathematical developments. 



