EQUATION AND THE NATURE OF COHESION. 17 



TABLE 1. 



Test of relationship that (P c -j- a/r e 2 )/(a/F c 2 ) = L\{L — E) (at 

 1\) = 7.5/6.5 = 1.154. 



Substance 



Isopentane 



Pentane 



Diisopropyl 



Hexane 



Heptane 



Octane 



Diisobutyl 



Methyl formate . . . . 



Ethyl formate 



Methyl acetate 



Methyl propionate . . 



Ethyl acetate 



Propyl formate . . . . 

 Methyl butyrate . . . 

 Methyl iso-butyrate . 

 Ethyl propionate . . . 



Propyl acetate 



llexamethylene . . . . 



i'7-Benzene 



Benzene 



67-Benzene 



i?;-Benzene 



Ether 



CCl 4 



SnCl± 



f 



183 

 195 

 220 

 230 



200 

 290 

 274 

 200 



230 



230 

 256 



2 17 

 260 

 270 

 265 



270 

 275 

 279 



280 

 2 s() 

 270 



/. 



-f 



4 . 8 

 2.2 

 7.35 

 4.8 

 0.85 

 6.2 

 2 . 8 

 14. I 

 5.2 



3.1 

 4. S 5 

 11.3 



2.55 

 2.9 

 1.2 

 1.0 

 6.55 

 8.5 

 89.2 



270 



127. 



2 



190 



3 



s 



260 



3 



15 



280 



38 



7 



L 



41.27 

 15.66 

 22.14 

 19.73 

 21 .'90 

 19.10 

 14.24 

 38.80 

 22.79 

 20.99 

 12.70 

 17.12 

 21 . 02 

 26.96 

 14.53 

 15.65 

 11.73 

 11.78 

 20.82 

 27.43 

 52.50 

 44 . 34 

 19.38 

 10.43 

 15.60 



L—E 



35.39 

 13.38 

 is. 95 



16. 9 s 

 19.02 

 10.06 

 12.39 

 33.18 

 19.51 

 18.10 

 10.98 

 14.82 

 18.17 

 23.48 

 12.01 

 13.64 

 10.20 

 10.07 



17. 9 s 

 23.45 

 45. SO 

 38.91 

 J . 



8.90 

 13.45 



m 



L—E) 



i 



106 



i 



170 



i 



168 



i 



162 



l 



1 5 1 



i 



147 



i 



149 



i 



169 



i 



168 



i 



.159 



i 



157 



i 



154 



i 



.157 



i 



. 148 



i 



152 



i 



148 



i 



150 



i 



.170 



i 



158 



i 



106 



i 



148 



i 



.140 



i 



107 



i 



172 



i 



.160 



Mean 



1.158 



An inspection of Table 1 shows that the ratio of L\{L — E) does 

 indeed approach a constant value some three or four degrees below 

 the critical temperature. The mean value is 1.158 which is about 

 0.4 °/ o higher than 1 had expected, or the value of 1.154 which 

 is the ratio of 7.5/0.5 ; but the constancy of this ratio must be 

 regarded, I think, as on the whole satisfactory. The maximum devia- 

 tion from the mean, disregarding I?r-Benzene, is not more than 1 °/ . 



From these figures we discover two important facts. First that 



Verhand. der Kon. Al<ad. v. Wetensch. (!<■ Sectie) Dl. XII N°. 4. D2 



