POLYMORPHISM AT HIGH PRESSURES. 



107 



to be set up again after so many transitions had run as to jamb the 

 carbamide tightly against the walls of the shell. At higher tempera- 

 tures there is another source of error in measurements of Av because 

 of incipient decomposition. 



012345678 

 Pressure, kgm./cm.^ x 10^ 

 Carbamide 



Figure 8. Carbamide. The observed equilibrium pressures and tempera- 

 tures. 



Temperature 

 Carbamide 



120° 



Figure 9. Carbamide. The observed differences of volume. 



The equilibrium curves, with the observed pressure and tempera- 

 ture points, are shown in Figure 8, the values of Av determined after 

 the proper procedure had been discovered are shown in Figure 9, the 



