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groups in itself, but also by their position in regard to each other. 

 It also follows that Ostavald's method for the calculation of the 

 dissociation constants of disubstituted acids from those of the mono- 

 substituted acids cannot be correct as is apparent from the sub- 

 joined table: 



In the two vicinal acids 2,3 and 2,6 the deviations from the cal- 

 culated value are particularly large, as I have previously shown for 

 other vicinal substituted acids (Rec. 20, 363). 



In view of the comparison of the figures for the dissociation 

 constants of these acids and for their esterification constants, it seemed 

 desirable to have also an opinion as to the molecular conductivity 

 of these acids in alcoholic solution. They were, therefore dissolved in 

 95 vol. 7o alcohol to a N./,oo solution and the conductivity power 

 of those liquids was determined at 25°. The subjoined table shows 

 the values found and also those of the aqueous solutions of the 

 same concentration and temperature : 



from which it appears that also in alcoholic solution the acids with 

 an ortho-placed nitro-group are more ionised than the others. 



Esterification velocitij. The method followed was that of Goldschmidt, 

 who dissolved the acid in a large excess of alcohol and used hydro- 

 chloric acid as catalyzer. The alcoholic hydrochloric acid used here 



