BRIDGMAN. — THERMODYNAMIC PROPERTIES OF LIQUIDS. 



47 



pinched off at a high pressure because of fatigue, so that there is only- 

 one reading for the dilatation at the two highest pressui'es. The 

 agreement between the two sets at the lower pressures was good 

 enough however, so that it did not seem necessary to set the appara- 

 tus up again merely to repeat these last two readings. 



■ffrti#fJ44ffUf| 



1.00 



E 



<j 



oT 

 E 



o 

 > 



2 3 4 5 6 7 8 9 10 U 12 

 Pressure, kgm. / cm.^ x 10^ 

 Propyl Alcohol 



Figure 10. Propyl Alcohol. Volume at 20°, 40°, 60°, and 80° plotted 

 against pressure. The lower curve gives the volume at 20°. 



The average discrepancy between the piston displacement of the two 

 determinations of the compressibility at high pressures was 0.0026 

 inch on a total stroke of 2 inches. The average discrepancy in the 

 displacements at constant pressure corresponding to an increase of 

 temperature of 20° was 0.0018 inch on a mean displacement of about 

 0.070 inch. 



The reduction factor from the mathematical formula was 0.8726. 



The density at 0° is 0.8179. The constants of the dilatation for- 

 mula are: a = 0.02774, b = 0.05497, c = — O.OyMl. These values of 

 a, b, and c are from results of Zahnder,^^ who gives for the density 

 at 0° 0.8177, instead of 0.8179 above. The agreement is virtually 

 perfect. In addition we have data by Naccari and Pagliani^^ who 

 give for the density at 0° 0.8203, and for the volume at 20°, 40°, 60°, 

 and 80°, 1.020, 1.042, 1.064, and 1.090 respectively, against 1.017, 

 1.038, 1.061, and 1.0865 adopted from Zahnder's formula above. 



21 Zahnder, Lieb. Ann., 225, 114-193 (1882). 



22 Naccari and Pagliani. Att. R. Ace. dell. Sc, 16 (Sept. 1881). 



