spinodal curve and on the curve .. „ . Vgf = 0. 



( 14 ) 



The z;,,?;-curve denoted by T^, relating to \\\q maximum temperature 

 of subUïiiation, consists of two branches, which pass continuously 

 into each other. The points of intersection with the connodal line 

 a b indicate the vapour phases and those with the connodal line cd 

 the liquid phases. In this way we get two pairs of fluid phases which 

 can coexist with the solid compound at the same temperature. 



At the place where the two branches of the v,,i'-line cut the locus 



With increase of temperature these branches draw nearer to each 

 other, and when they would touch, intersection takes place; this is 

 here supposed to take place for the v,x-\\ne denoted by 1\. This 

 point of intersection is the point q^, it lies therefore both on the 



V 



If we now proceed to higher temperatures, detachment takes 

 place, and the ?;,.i'-figure consists of two separate branches, one 

 of which, viz. the vapour branch is closed. This case is represented 

 by the v,x-ïme 1\, for which it is also assumed, that this temperature is 

 the minimum-melting jwint of the compound, which follows from the 

 fact that the liquid branch of the v,a;-\me T^, simultaneously cuts 

 the connodal line cd and the line of the compound. 



With rise of temperature the closed i\.i'-line contracts, and the 

 corresponding liquid branch descends. The points of intersection of 

 the closed vapour branch and the liquid branch with the connodal 

 curves draw nearer and nearer to each other, and at a certain 

 temperature the two branches will show contact. The closed vapour 

 branch touches the connodal curve a b and the liquid branch the 

 connodal curve c d. This is represented by the v,.i'-figure T^, which 

 represents the condition at the maximum-threephase-temperature, at 

 which the points of contact on the connodal curves and the point 

 for the solid substance must lie in one line. 



At higher temperature no three phase equilibrium is possible any 

 longer, and both the closed vapour branch and the liquid branch 

 have got detached from the connodal curves. The liquid branch 

 descends lower and lower, and the closed branch contracts more and 

 more, and vanishes as a point in q^, where the upper branch of the 



spinodal curve and the curve ^r- ^sf = intersect. 



ö> 

 If we now also indicate the locus of the points where ^— . Wgf = 



