40 Dr. A. Ferguson on the Variation of 



variation in n, at moderate temperatures, has not much 

 «j3ect on the computed values of T or of b. 



The figure, which is drawn to scale, shows a few of the 

 curves obtained by the process outlined above, and their close 

 approach to parallelism serves further to emphasise the 

 amallness of the variations in n. 



The accuracy with which equation (iii.) fits the observed 

 values for the surface-tension is sufficiently shown by Tables 

 II. and III. below. For convenience of comparison the 

 results obtained by the use of Van der Waals' equation (v.) 

 are also given. 



Table II. 





Benzene 



{T=T (1 



.-•003472 d) l ' 2l8 \. 





e (Cent.). 



T obs. 



A. F. 



V. d 



. W. 



T calc. 



Diff. 



T calc. 



Diff. 



0° 





30-28 









80 



20-28 



20-36 



fO-08 



20-39 



+0-11 



100 



18-02 



18-01 



-0-01 



18-01 



-001 



120 



15-71 



15-71 



+000 



1569 



-0-02 



140 



13-45 



13-46 



+0-01 



1343 



-002 



160 



11-29 



11-28 



-001 



11-24 



-005 



180 



915 



9-17 



4-002 



913 



-002 



200 



7-17 



7*15 



-0-02 



711 



-006 



220 



5-25 



5-22 



-0-03 



519 



-006 



240 



341 



3-41 



+0-00 



3-39 



-002 



260 



1-75 



177 



4-002 



1-76 



+001 



280 



J __- 



0-29 



0-39 



+010 



0-40 



+0-11 



