112 



BRIDGMAN. 



slightly pinkish, but it had a melting point 0.02° higher than that of 

 the first lot, and a trifle higher than any previously recorded for 

 phenol. The purity is apparently, therefore, as great as can be 

 obtained by ordinary means. The pinkish specimen was used for 

 the high pressure determinations. This specimen was not perfectly 

 pure, however, because some rounding of the corners could be detected. 

 It was melted into the inverted steel shell and pressure transmitted 

 to it by mercury. Four different fillings of the apparatus were used; 

 one for the point at low pressures and the other three for the points 

 at high pressures. The quantities used varied from 13.5 to 17.5 gm. 



23456789 10 1112 

 Pressure, kgm./cm.^ x 10^ 



Phenol 



Figure 27. Phenol. The observed equilibrium temperatures and pressures. 



The experimental values of pressure and temperature are shown in 

 Figure 27, the experimental values of AV in Figure 28, the computed 

 values of AH and AE in Figure 29, and the numerical values are col- 

 lected in Table XIII. No points have been discarded. ( 



It has been known for some time that phenol has two modifications. 

 These were discovered by Tammann,^* who has written two papers on 



24 G. Tammami, 

 11). 



'K. und S.," 308, and ZS. phys. Chem. 75, 75-80 (1910- 



