ras 



the point ƒ is now FfF' and its opposite angle. Tiie curves a.vf 

 and ul>/ are both drawn within this angle. 



Similar contemplations apply also to the three cnrves which inter- 

 sect each other in the point f^. 



A relation exists also between the position of the cnrves in the 

 point / and in the point f\. This however we shall not discuss 

 any further here. 



In all our previous considerations we have always contem- 

 plated saturationcurves under their own vaponrpressure and boiling 

 pointcurves of tv. simple form, nl. curves existing only of a 

 single branch. Under definite circumstances however also curves 

 of a more composite form may occur. Here we shall briefly treat 

 such a boilingpointcnrve. 



We take a ternary mixture, wherein the system L — G has a 

 ternary point of minimnm pressure, therefore also a ternary point 

 of maximum temperature. 



We suppose now that at a definile P ^nd 7' the relations of 

 fig. 1 (HI) occur. Herein we find a closed region L — G and within 

 the liquid region the saturation line of the compound F. We 

 keep the pressure constant and raise the temperature ; the liquid- 

 region then becomes smaller or in other words : 



The liquid curve of the region L — 6^ contracts. Further we assume 

 that heat is i-equired for dissolving F, so that the saturation^urve 

 of F contracts also. 



If the satiirationcurve of F contracts more rapidly than the liquid 

 curve of the region L — G, then no points of intersection arise and 

 therefore under the assumed pressure also no boilingpointcnrve of 

 F exists. 



When the liquidcurve of the region L — (t contracts more rapidly 

 than the saturationcurve of F, at a definite temperature 7',, contact 

 takes place. We imagine in fig. 1 (III) that the curves are shifted 

 in such a way, that anywhere on the left side of F a point of 

 contact m arises. If the tem])erature rises still more, now two points 

 of intersection arise, which move away from each other and shift 

 towards the right. Now different cases may occur of which we have 

 already treated some in communication ;,II1). We assume that on a 

 further increase of T the two points of intersection coincide any- 

 where on the right side of F in a point M. 



We may now obtain a diagram as fig. 4. While at the tenqie- 

 rature T^ the saturationcurve of F is surrounded by the liquidcurve 

 of the region L — G, at the temperature l\\i (fig. 4) it is just the 



