the Unit-Stere Theory. 



343 



molecular critical volumes, influences are introduced which 

 have similar effects to those of constant errors. This is par- 

 ticularly the case with octane, which possesses values of V/V K> 

 consistently lower than those for hexane and heptane. If 

 now the volumes under the equal reduced pressure '002949, 

 viz., that at which the additive law is very approximately 

 true, be taken as standard, the multiples that the volumes at 

 higher reduced pressures make with this standard are much 

 more nearly equal, and further, the divergences are seen to 

 exactly follow those of V/W. 



XVI.— Table of Comparison of V/V K and V/V, V the 

 volumes at equal reduced pressure '002949. 



•002949 



V/V K (Young). 



V/V (Le Bas). 



: C 5 H 12 . 



... 



C B H U . 



•3494 



C T H 1G . 

 •3475 



^8^18' 



•3443 



C 6 H U . 



C T H 1G . 



C S H 18 . 



1-C0O 



1-000 



1-000 



•005898 



1 



... 



•3563 



•3545 



•3513 



1020 



1-020 



1020 



•011795 



i 1662 



■3649 



•3631 



•3597 



1044 



1045 



1-045 i 



•022411 



! -3756 



•3746 



•3727 



3693 



1-072 



1-073 



1-072 



•44232 



; '4976 



•4969 



•4941 



•4932 



1-419 



1-422 



1-432 ; 



•58978 



•5380 



•5357 



•5336 



•5324 



1-533 



1-536 



1-547 



•73721 



, -5872 



•5851 



•5830 



•5818 



1-674 



1-678 



1-689 



•82568 



•6268 



•6258 



•6230 



•6243 



1-790 



1-793 



1-813 



1-00000 



1-0000 



i 



1-0000 



1-0000 



1-0000 



2-86 



2-87 



290 



The ratios V/V show that hexane and heptane follow one 

 another very closely right up to the critical point, and on the 

 other hand, octane, while agreeing with the other two hvdro- 

 carbons from P/P K = '002949 to '022411, shows higher values 

 of the ratio from P/P K = -44232 to 1. y 



This is exactly what the values of the ratio ^ teach. 



The conclusions are as follows : — 



(a) The molecular volumes of the hydrocarbons from 



pentane to octane are very nearly proportional to 

 their respective valency numbers under conditions of 

 corresponding pressures. 



(b) The law of corresponding states and that of additivity 



are interdependent, and they may no doubt be 

 similarly explained. 



(c) The ratios V/W are very well adapted to show the 



extent of constitutive differences. 

 (a 7 ) The law of additivity is the more closely followed the 

 further from the critical point that observations are 

 made in this series at any rate. 



