.S47 



represent tlie quantity of .1 of a phase by .i; (or .r,), llio quanlit^- of 

 C by 1/ (or yi), and the quantity of B by '1 — .c — // (or l — .<'i -//,). 

 We put, tlierefore, the origin of our coordinatesystein in the angle 

 point B, the A'- axis along the side BA, and the F-axis along (he 

 side BC of the triangle. To the saturationcurvc under its own 

 vapourpressure of B then applies : 



{.vr rf r/s) dx + {.vs + ijt) dy = AdP (3) 



\{x, - x) T + {y^ - y) .] dx -f \{x^ - x) s + (//, - //) t\ dy =z CdP (4) 



In order to have the boilingpoint curves, we must replace in (3) 

 AdP by —BdT and CdP by — DdT. 



In the terminating point of both these curves on the side BC, 

 X = 0. We then find : 



fi _ Zi h ^'h 



RTydxJ,,=o LVy ^" R'n' \dx ).,^(, LWy ' ^^^ 



In the terminating point of both these curves on the side BA, 

 y :=0. We then tlnd : 



(^) 



From this it is easily found, that the relation 11 (XI) and the 

 rules deduced from this apply also on the addition of a (liird 

 substance to the binary equilibrium B -\- L -\- G. 



We may in the same way as in the previous comtnunication in- 

 troduce also in (5) and (6) the perspective concentrations S and ^\ 

 of the new substance. Then S is the part cut off by the line />- 

 liquid, Si the part cut off by the line /i-vapour from the side (A 

 (fig. 2). When the binary equilibrium B -\- L -^ (i is situated on 

 j5C,>i' = 0), so that A is the new substance, these parts must of 

 course been measured from C; when the binary equilibrium is situ- 

 ated on BA iy = 0), so that C is the new substance, they must be 

 measured from A. 



When the 'binary equilibrium B -\- L -{- G is situated on the side 

 BC{x = 0), we find 



