(125 ) 



value of q is lowered, (lie points 6 and 3 draw nearer to each 

 other, and they coincide for the loop-J-line which passes through 



the point of intersection of = and - — - 



dx* dxdv 



0. Then the bran- 



ches c and d intersect at an acute angle, just as the branches ƒ and 

 g. When (j is lowered further, and the 7-line has split up into two 

 separate portions, the p-line too divides into two separate parts; the 

 branch g is then the continuation of c, and the branch ƒ the con- 

 tinuation of (/. Fig. 21 illustrates the course of p as function of v 



Fig. 21. 



for such a ry-line Which has divided into two separate portions; then 

 the branches c, g, which have united to one branch cut the united 

 branch (/, ƒ, ami the branch e. 



When applying Maxwell's rule for the determination of the binodal 

 line we are confronted with some difficulties, which I will now 

 discuss. Already when the /(-line runs as is represented by the 

 branches e, ƒ and y in tig. 20, so when the middle one of the 3 

 branches cuts one of the outside lines, we must pay proper attention 

 to the sign of the areas when applying the rule for drawing Maxwell's 

 line. If the straight line is drawn lower than the point of intersection 

 of e and ƒ, the area below this line, which according to the rule 

 must be equal to the area above this line, must of course he all 

 that is contained between the branches g and ƒ below this line. 

 But the area above the line, which consists of two parts, viz. the 

 area of the loop, and the part that lies below the double point above 

 the line, must not be considered as the sum of these two parts. On 

 account of the branch ƒ running back, the latter part # must be taken 



8* 



