124 Dr. E. Obach on Relationship between Specific 



Table VII. 



Comparison of Specific Inductive Capacities calculated by the formula 



T 

 K=C' 1 r^ with those observed by Tereschin. 



Description of Series. 



Alcohol radical. 



Methyl. 



Ethyl. 



Propyl. 



Isobutyl. 



Aruyl. 



f Calculated 



Formates \ 



y Observed 



10-8 

 9-9 



9-4 

 9-1 



8-6 



7-8 

 8-4 



Iso. 7-3 



77 





f Calculated 



7-6 



7-8 



6-7 

 6-5 



62 

 63 



5-7 

 5-8 



Iso. 5-3 

 5-2 



Acetates I 







6-9 



7-2 



6*5 

 6-5 



6-2 



5-8 

 60 



Iso. 5-6 



5-2 ' 



Benzoates -j 



^ Observed 





f Calculated 



36-2 

 32-7 



261 



25-8 



21-1 



22-8 



17-9 



15-9 

 15-9 



Alcohols \ 



1 Observed 





The series of chemical compounds so far considered are all 

 characterized by the fact that the alcohol radicals are indi- 

 rectly linked to the carbon through the interposition of an 

 oxygen atom ; but if the radicals are directly bound to the 

 carbon, which, for instance, is the case with the benzene 

 hydrocarbons, proportionality between specific inductive 

 capacity and latent heat of vaporization no longer holds good. 

 This is evident on comparing the latent heats of these hydro- 

 carbons found by Schift' with the inductive capacities obtained 

 by Negreano *, where, with increasing molecular weight of 

 the series, the former diminish and the latter slowly rise. 



Besides the compounds which have already been mentioned 

 only a few more remain, for which fairly reliable values of 

 both specific induction and latent heat exist : these are ethylic 

 ether, carbon tetrachloride, carbon disulphide, and oil of tur- 

 pentine ; but even for these bodies the inductive capacities 

 are by no means certain, as the results obtained by different 

 investigators and different methods show considerable varia- 

 tions. Carbon tetrachloride has been examined by Tereschin, 



* Comptes Rendus, vol. civ. pp. 423-425 (1887). 



