( 460 ) 



ilot at all dissociated, that iiiiniiiiuin would coincide with the com- 

 position of the compound. 



P 



Fcj. 2 



The three-phase lines would then appear about as shown in Fig. 2. 

 Instead of one continuous line for the compound, there would be 

 two branches sharj)ly meeting in F, CF and DF, both exhibiting 

 the character of branch 1, and therefore the order Cy/>,S' of the three 

 phases, and both becoming tangent in F, to the melting point line. 



The sharp meeting in F is caused by the fact that there is no 

 continuity between liquids or vapours containing an excess of A or 

 of B, if the compound itself on its transformation into liquid w 

 vapour, that is in F. remains totally undissociated and tlierefore con- 

 tains no trace of .4 or B in the free state. In this case i*^ is a 

 triple ]ioint foi* the compound. 



In case of the least trace of dissociation we, however, get continuity 

 and the branches CF and T)F unite to one three-|)hase line of the 

 compound, wdiicli therefore assumes tiie general form deduced by 

 Smits, and is represented in iig.'^3. The minimum in the vapour and 

 li(|uid line now, however, shifts towards a composition ditfering 

 from that of the compound, generally all the more as the volatility 

 of A and B ditfers more and the dissociation is greater. Unless 

 special intluences ^) decidedly modify the partial pressures of the 

 components in the lifjiiid phase, the minimum will genei'ally be 

 situated at the side of B. From the /.» , .I'-representation deduced foi- 

 this case by Smits, it will be easily seen that, proceeding along 



^) Such as the existence of several compounds. 



