( 651 ) 



with this we easily obtain for the case thai ./,. is not or I, the 

 course of the loci mentioned indicated in fig. 2. The dotted line 

 denotes the concentration of the solid phase P ; the lines J Q A' and 

 CQ D are the two branches of the spinodal curve, the two other lines 



joining A with B and C with 1) the branches of (~ ] = 0. When 



now x s =0 becomes, it is evident that at this rim the line D = 



must pass through the point where r-y = 0, and this point coincides, 



as is known, with the spinodal curve at the rim. The conclusion seems 

 obvious that'~the points Q and Q' ', the points of intersection of the 

 spinodal curve and D = have shifted towards the rim, and that, 

 accordingly, the points of detachment and contraction from figs. 2 — 8 of 

 Prof. Smits (loc. cit.) would have to lie at the rim. However, this 

 conclusion would not be correct. For the inference that where the 

 spinodal curve and D = intersect, on account of the geometrical 

 meaning of D — and N = 0, the latter must also intersect, does 



d s tb 



not hold good at the rim. This is in connection with r— becoming 



8> 

 zero and - — becoming infinite. If we introduce the value MRTIx, 



which the last quantity for x = gets, then N assumes the value : 



d> MRT /dp\ 



( Vs _ Vf ) — tVf — ( v/ _ { , s ) _ M r T 



ÖVÖ.V Xf \0.rj v 



and in general this expression will by no means be equal to zero 



/dp\ 



in the points where v/ = 0, as already appears from the simple 



. , , . MRT 



consideration that there can be no connection between - — , a 



vf— v s 



quantity which depends exclusively on the properties of the pure 



fdp\ 

 component and I r- 1 in the maximum and minimum points of its 



isotherm, because this latter quantity will also have to depend on 

 the properties of the second component. So the points Q and Q' 

 will certainly not lie at the rim, and in the points where D = 



follows : 



'dp\ d 5 lf> d a i|» fdq 





dxjr dvd.v o\c 2 \d.rjr fdv\ 



dp\ d> d 2 i|- /dq\ \dasj q 



dv J dv* d.vdv V dv 



