173 



diate vicinity of 6'; now we eciuate .<■ = '^, y =: i^ ajid ij^ = j/^. From 

 (8) follows : 



n. = Kn (4) 



wherein K is a constant fixed by (3). When we assume, as 

 in fig. i, that C is more volatile than B, the point (\ is situated 

 between C and a and A' is, therefore, smaller than 1. 



Now we equate in (1) P= Pc + ^^P^ ^^ = ?> y = n ^^^^ Ih = '*U ; 

 as in the point 6' f/=:= U^ is satisfied, it follows, that: 



- RT[t -^n- .iJ + [F-F/J c/P=. 

 or 



gJ,i\-K)r, = ~^^dP (5) 



In the immediate vicinity of the angular point 6' (fig. 1) curve (^(^/ is, 

 therefore, a straight small line. We find from (5) for the length of 

 the parts Cd and Ce -. 



Cdz= ' dP and Cez= ' dP . . . . (6) 



RT RT{\-K) ^ ^ 



As F,— F>0 and J-/v>0, it follows from (6) that Cc/ and Ce 

 are positive, when dP is negative, ki decrease of pressure curve cd 

 shifts therefore, within the triangle. From (6) follows :6(/: Ce = {i — K): 

 1 or, as /ir= 7^1 : ^ = Ce^ : Ce, we find : Cd = ee^. 



In order to examine the liqnidcurves going through the points 

 p and (/(fig. 1) in the vicinity of these points, we pnt in (1): • 



Z=U^Rl\clogw (7) 



we then find : 



d^ dU dU dZ, 



dx d y Ó y dy, 



For the liquidcurve of the region L-G we find from this: 



[.vr + {y-y,)si-RT]d.v-\-lvs + {y-y,)t]dy = . . (9) 



For the direction of this liquidcurve in its end on the side BC 

 (therefore x = 0) we find : 



dy {y—yx)s + RT 



dx iy—yi) t 



(10) 



When we call tp the angle, which this tangent forms with the 

 side BC (taken in the direction from B towaids C), we have, when 

 we imagine the componenttriangle rectangular in C: 



