( 231 ) 



curve and represent in ji' melasjable and iiiislahle j)liases. 3'^^. It may 

 toiicli as intermediate case the connodal curve of the transverse plait 

 in a point wljicii will he the |)lailpoint, as will a|)|)ear presently. 



As to the coui'se of the ii(|iiid part of the coulacl-curve we may 

 at once conclude, tliou^h this will he shown aflci'wards in a more 

 strikinfi' way, that two cases may occur. From the point on the 

 coimodal curve where it enters the li(|uid part of liie i|'-sin-face with 

 increasing' |)ressure, the curve will luimely move more and more 

 towards decreasing- values of .c, and tinally terminate at .i' = — 

 or it can move towards increasing- values of ./•. 

 • If we trace the tf'-curve for .r = i), and add a portion of the 



lig. 1 (a) 



i|;-cnrve for the solid body to the tigure, then if this portion has 

 position (a), so if the volume of the solid hody is smaller than 

 that of the liquid, only one hi-tangent can he drawn, and this 

 will represent a coexisting gas phase. If on the other hand the 

 added portion of the tf'-curve for the solid phase has j)Osition {//), 



fig. 1 (b) 



so if the volume of the solid i)hase is larger than that of the liquid, 

 two bi-tangents may be drawn. At low pressure, a coexisting gas 

 phase will oxist, and ;U high pi-cssurc a coexisting licpu'd. In the 

 latter case the li(|uid j)art (»f llic contact-curve will move towards 

 points for \\ liich ,/■ decrease^ when the j)i-essuiv increases. 



16* 



