418 Mr. H. Davies on some Applications of the 



The inductive power is thus a constant and numerically 

 equal to one tenth of the critical volume. The molecular 



inductive power given by ^ — r } •—? will obviously reduce to 



the same expression if V c is the critical volume of a gramme- 

 molecule. Table II. shows the values of the molecular 

 inductive power and one tenth the critical volume for a few 

 liquids. 



Table II. 



Liquid. 



Molecular 

 Inductive power. 



10' 



Benzeue , 



2679 



34-1 



22 



26-7 



33-54 



40-2 



261 



34-3 



24 



27-6 



34-5 



39 6 



Ether* 



Carbon bisulphide 



Carbon tetrachloride 



Toluene 







* Value of K for Ether is 2*12 at 180° C. This value was adopted 

 for calculation. 



The agreement here is quite satisfactory, only carbon 

 bisulphide being 10 per cent. out. 



3. Molecular Inductive Power and Critical Coefficient. 



Relationships should exist between molecular inductive 

 and refractive powers and the critical constants. Gruye f 

 showed that for some gases and liquids the molecular 



. T 



refractive power is 1*8 times the critical coefficient p^. 



-L C 



No theoretical basis has hitherto been published — so far as 

 the author is aware — for this relationship. One can be 

 obtained as follows. Prof. Young has calculated for many 

 substances the ratio between the ideal critical volume and 

 the actual critical volume. He defines the ideal critical 

 volume as the volume which the substance would occupy at 

 its critical temperature and pressure if it was an ideal gas. 

 The values he obtains have as their mean 3*7. Let V c be 



f Guye, Ann. Chem. Phys. (6) xxi. p. 222 (1890). 



