BRIDGMAN. — THERMODYNAMIC PROPERTIES OF LIQUIDS. 



51 



of the present determinations at the low pressures is considered; the 

 agreement is better than the agreenient of those values which have 

 been taken directly from the work of Amagat. 



The volume of isobutyl alcohol as a function of pressure and tem- 

 perature is shown in Table VI and in Figure 11. 



1.10 



1.00 



E 



u 



<u 



E 



O 

 > 



1 2 3 4 5 6 7 8 9 10 11 12 



Pressure, kgm. / cm.^ x 10* 



Isobutyl Alcohol 



Figure 11. Isobutyl Alcohol. Volume at 20°, 40°, 60°, and 80° plotted 

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



The compressibility determinations of Pagliani and Palazzo were 

 fortunately made with isobutyl instead of normal butyl alcohol. 

 They give for 20°, 40°, 60°, and 80° the values 0.0492, O.O3IO3, O.O3II8, 

 and O.O3I37. The values required to give the values of AV listed in 

 the tables are 0.0,122, O.OJSS, O.O3I44, and 0.0,164. The discrepancy 

 is large, too large. Instead, however, of taking the average of the 

 discordant results, it was preferred to retain the values consistent 

 with the table, it being understood that the initial values between 1 

 and 500 kgm., both for the total change of volume and for the compres- 

 sibility are probably in error. Abnormal variations of compressi- 

 bility, such as the rapid initial decrease "with pressure, may possibly 

 explain part of the discrepanc3^ We have also a value of Rontgen 

 for the compressibility at 20°, O.O496, which is in very much better 

 agreement with the value of Pagliani and Palazzo than the present 

 value. The recent value of Richards is practically the same as 

 Rontgen's. 



For Cp we have a larger number of measurements than we sho\ild 



