17fi 



pressure 

 111 m I 

 Fiudier 



substance F, tlie vtipoiir ?Zi must he situated 

 between F and n. Consecjuently we have 

 here the case that the vapour, corresponding 

 in fig. 1 Avitli the licpiid q, is represented 

 by q■^ ; the liquid-curve of the legion L — G 

 going through tjjc point q can, tiierefore, 

 bo represented by qq^' (fig. 1). It follows 

 from this position of qq^' that on furtluu' 

 decrease of pressure the liquidcurve of the 

 region L — G must touch curve pq in a 

 point m (fig. 1) ; in fig. 2 this point of 

 contact is also represented by m. Previously 

 we have seen that the vapour corresponding 

 with such a point of contact lias the com- 

 position F; in fig. 2 m and F are joined 

 for this reason by a conjugation-line. 



It follows from this deduction that the 



is a minimum in the point m of fig. 2 and increases from 



lie direction of the arrows, consequently towards n and h. 



it is evident that the vapoui-jiressure in A is higher than in ??. 



Vm. 2. 



2. The tenq)ei-ature is higher than the |)oint of maximum subli- 

 mation Tk and lower than the minimum-ineltingpoint 7V of the 

 substance F. 



In a similar way as we have deduced the general case fig. 7 f I), 

 we now find with the aid of fig. i a diagram as fig. 3. Curve 

 hachn is the saturationcurve under its 

 own vapour-pressure, Ji^ a^ c^ hy n^ is the 

 cori-esponding straight vapour-line. As 

 we have assumed that the temperature 

 is higher than Tk but lower than Tf, 

 F must, as in fig. 3, be situated bet w^een 

 n and n^. Tiierefore, here we have the 

 case that the vapour, corresponding in 

 fig. J with the li(|uid q. is represented 

 by q^ ; the liquid-curve of the region 

 L — G going through the point q may, 

 therefore, be represented by qq'^ (fig. I). 

 It follows from this position of qq\ that 

 on further decrease of pressure the liquid- 

 curve of the region L—G no more 

 intersects curve pq. Fig. 3. 



