264 



MOREY 



ART. G 



compound formed between the two components will not be con- 

 sidered. It is not readily formed; metastable equilibria be- 

 tween phenol and water in which it is not formed are more 

 easUy realized than the stable ones, with formation of the 

 compound; and its consideration would involve no new prin- 

 ciples. On addition of phenol to water, the ice curve is first 

 traced, down to the eutectic between ice and phenol crystals. 

 The invariant point at which both ice and phenol can coexist, 



7<? 



I 



in 



-^ 



,i,^2l-. 



30 £0 70 90 

 COMPOSir/ON 



A 



C 



Fig. 4. The binary system, H20-phenol. Diagrams A, J5, and C are 

 the projections of the curves representing univariant equilibria in the 

 solid "p-i-x model on the -p-x, p-t, and t-x planes, respectively. 



together with solution and vapor, is at —1.2° (Fig. 4) and at a 

 concentration of phenol of less than one per cent. As the 

 temperature is raised above this point, the solubility of phenol 

 increases slightly, until at 1.7° the saturated solution contains 

 about 1.8 per cent phenol. At this temperature the solid 

 phenol in equilibrium with the solution melts, taking up water, 

 and forming a second liquid layer. We have then four phases, 

 solid phenol, a liquid containing 1.8 per cent phenol, a second 



