834 



represents L^ and L, becoming- identical, P, represents Z>, and G 



,■ s 



Fig. 8a. 



Fig. 86. 



becoming identical; the plait of /\ has disappeared in this last point 

 within the longitudinal plait; it has been omitted for the sake of 

 the lucidily of the tignres. The li(|nid coexisting with the thiid phase 

 P, is indicated by A. The nodal lines /i 6' in the plait 7^,7^4 pi"esent 

 a situation corresponding to fig. 5^/ ; the nodal lines DE to tig. 4<'i, 

 It follows from this that a nodal line may be di-awn between BC 

 and DE, the prolongation of which passes through «S {EG in the 

 figs. 8a and %h). Hence in the points E and G a possibly occurring 

 binodal line for fluid phases coexisting with solid touches the binodal 

 line fluid-fluid. (See ^ 4). In fig. 8a the nodal line EG lies below 

 P^A, in fig. 86 it lies above it. 



When we now inquire into the course of the binodal line solid- 

 fluid, all the possible situations can be easily surveyed by rolling a 

 tangent plane for continually decreasing values of if's over the surface. 

 When the i|;-valiie of .^ is chosen high, the tangent curve will only 

 intersect the plait on the riglithand of DE\ with lower value of 

 i|Js a curve will make its appearance which also passes through P^\ 

 further the curve will inteisect the plait both in the neighbourhood 

 of 7^, and in the neighbourhood of DE. Such a situation is repre- 

 sented by the curve indicated by crosses. When \\\ is made to shift 

 further, we get a curve passing through 7^, indicated by a line of 

 dashes. Finally the tangent curve will move in such a way that 

 the two points of intersection on the two binodal branches approach 

 each other, and at the coincidence in E and G contact of the two 

 binodal curves takes place; the curve for solid-fluid lies in i^ out- 

 side the binodal line fluid-fluid and is stable; for (z it lies, however, 

 in the covered region. By the aid of the rules of § 2 it may be 

 derived that the traced situations are the correct ones. It should, 

 however, be pointed out that according to these rules the binodal 

 lines in /*, touch and intersect. 



