and the Properties of Liquids. 



571 



benzene, and chlorobenzene were found to be equal to 1*003, 

 1*004, 1-002, and 1*104, respectively ; they are practically 

 equal to one another, as they should be, and differ little from 

 unity. The fundamental form of Eotvos' equation, it will 

 be seen, gives \ = at the critical point. 



It may be mentioned that a fair agreement with the facts 

 is also obtained by using the empirical equation 



k_ 

 m 21 ' 6 



\ — (n 2 /' 3 — n 2 / 3 



)(T e -T). 



Another equation for the surface tension of interest may 

 be pointed out here. If </> 2 is put equal to 



in the surface tension equation we obtain 



,..(S)'W(^)>€ + -' ). 



By means of equation (6) it may be transformed into 



where K is a universal constant. At corresponding states 



we should therefore have that —(— — — ) has the same 



p \ m J 



value for all liquids. That this is approximately the case is 

 shown by Table II. 



Table II. 





2T C 

 3 • 



X. 



Px-p-r 



m. 



"'■ 



X/Px-P 2 \V 3 



2>c\ m 1 



Ether 



311-7 

 324-7 

 371*0 

 374-3 

 4220 



14-19 

 19-80 

 1669 



17-87 

 17-78 



•6857 

 •9250 

 1-4285 

 •7881 

 •9544 



74 



60 

 154 



78 

 1125 



3628 

 5662 

 44-97 

 47-89 

 44-62 



8-4X10" 2 

 8-7 „ 

 78 „ 

 8-1 „ 

 8-1 „ 



Methyl formate 



Carbon tetrachloride. 



Chlorobenzene 





