Prof. W. Ostwald's Electrochemical Researches. 105 



radicles from the molecules, and that the parts of molecules 

 set free again change places with others. The more fre- 

 quently the ions can interchange the more rapidly will elec- 

 tricity be conducted, because the electricity can only pass 

 along with the ions. Now as, according to Faraday's law, 

 the ions always transmit the same quantity of electricity 

 independently of their chemical character, it must be con- 

 cluded from the theories of Clausius and Williamson that the 

 velocities of reactions taking place under the influence of 

 acids must be proportional to the velocities with which the 

 acids transmit equal quantities of electricity, i. e. to the elec- 

 trical conductivities of the acids*. 



This inference from the theories of Williamson and Clausius 

 has been verified by the author, by a series of measurements 

 of the electrical conductivities of acids the velocities of reac- 

 tions of which he had already determined ; the chief reactions 

 in question were the catalytic decomposition of methylic acetate 

 and the inversion of cane-sugar. The following Table (p. 106) 

 presents the results. Columns I. and II. give the velocities 

 of the reactions referred to that of hydrochloric acid as 100 ; 

 the numbers hold good for solutions containing respectively 

 § and -| equivalents, in grammes, in 1000 cubic centimetres. 

 Columns III., IV., and V. give the electrical conductivities, 

 determined by the method of Kohlrausch, referred to that of 

 hydrochloric acid as 100 ; the numbers in III. apply to 

 normal solutions containing one gram-equivalent in 1000 cubic, 

 centim. ; in IV., to ^ normal ; and in V., to t Jq normal 

 solutions. 



These numbers show that the electrical conductivities of the 

 acids in the table are proportional to the velocities of the 

 change of methylic acetate into methylic alcohol and acetic 

 acid, and the inversion of cane-sugar, brought about by these 

 acids. The differences between the actual numbers in columns 

 I., II., III., and columns IY. and V., may be explained by 

 the occurrence of secondary actions among the first products 

 (methyl alcohol, acetic acid, inverted sugar) of the two changes, 

 measurements of the velocities of which were made. But 

 determinations of the electrical conductivities of the acids are 

 entirely free from the influences of secondary changes. By 

 means of these determinations accurate values may be found 

 for the affinity-constants of the acids. These values are as 

 important in the theory of chemical affinity as the values of 

 the equivalent weights of the elements are in Stoi'chiometry. 



* This conclusion has been already stated by Arrhenius {JBigh. till. V. 

 Svensh. Ah. Hand. 8, Nos. 13 & 14, 1884) ; but it was based on a com- 

 paratively small number of experiments. 



