( 386 ) 



longer, because it disappears there above the triangle of the three 

 phases-pressure. It appears then as the beginning point of the three 

 phases-pressure. 



Led by the thought that if the temperature rises a plaitpoint can 

 onlv appear on the surface ip^ if a plait splits into two parts or can 

 disappear, if two plaitpoints fall together, and that therefore a branch 

 of a plaitpointcurve can never end in any other point than in the 

 critical points of the components or in a point at an infinite dis- 

 tance. I have occupied myself with the question how the two sepa- 

 rate branches can be joined into one curve. The simplest way of 

 doing this is by joining the two branches, as is indicated by the 

 dotted line in the figure. 



The vertical lines, between which the closed part of the curve lies, 

 represent then a maximum and a minimum temperature. The mini- 

 mum temperature is the temperature at which the transverse plait 

 splits into two parts and from which a plaitpoint starts to the 

 rio-ht and to the left towards the critical point of the components. 

 The greatest irregularity of the point, going towards Cg, the critical 

 point of alcohol, is that in its course it approaches a little nearer 

 to the side of the small volumes. But the point, describing its way 

 to Cz has greater irregularities. At the maximum temperature it 

 meets another, which has come from the opposite direction, starting 

 from C'l and at their meeting its movement ends. The three branches 

 mentioned however, form a continuous curve on the w-pltine. 



At a given temperature, between the minimum and the maxi- 

 mum temperature, the projection of the spinodal curve consists of 

 two separate parts. One part forms a small closed curve round the 

 point where the meeting will take place; the other part has an 

 almost regular form. 



But the two plait-points, which belong to the first part, are quite 

 covered by the ruled surface of the connodal curve of the second 

 part. Moreover the peculiarity presents itself that there is a great 

 distance between the spinodal and the connodal curve- a distance 

 great enough to contain the closed branch of the spinodal curve. 

 After I had convinced myself that an exact description of the pheno- 

 menon has been given in what I have said before, the question was 

 to be solved, how this would agree with the fact, which I had 

 remarked before. I have remarked (Molekulartheorie Y 2) that for 

 a mixture of two substances there can only be question of a maxi- 

 mum or of a minimumtemperature, but that the existence of the 

 two at once is excluded. I think that we must look for the expla- 

 nation of this in the fact that in the experiments of Kuknkn and 



