206 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



substance is associated with the cation. 4 In the case of sulphur, which 

 element is closely related to oxygen, salts of the type R 3 SX are well 

 known. 



Correspondingly, the ammonium salts dissolved in liquid ammonia 

 exhibit all the properties of acids, and the ammonium ion exhibits the 

 properties characteristic of the hydrogen ion. 5 If this conception regard- 

 ing the nature of the hydrogen ion is correct, we should expect solutions 

 of the acids in solvents, which do not possess the power of forming com- 

 plexes of the type R 3 + , to be relatively poor conductors. Such indeed 

 appears to be the case. Dissolved in the alcohols, hydrogen chloride 

 conducts fairly well; while dissolved in acetone, 6 hydrogen chloride 

 yields a solution of very low conducting power. In view of the fairly 

 high dielectric constant of acetone, it is difficult to account for this be- 

 havior of the acid except on the assumption that in this case there is 

 little tendency to form the oxonium complex. There are no data to indi- 

 cate that hydrogen chloride is a conductor when dissolved in sulphur 

 dioxide or any other solvent which does not contain oxygen, nitrogen or 

 other atoms capable of forming complexes. 



These various facts indicate that the hydrogen ion in water is, in 

 fact, not a hydrogen ion, but an oxonium ion. Whether the charge is 

 associated with the hydrogen or with the oxygen atom cannot be deter- 

 mined in this case any more than it can in that of the similar ammonium 

 salts. It appears likely, however, that in salts of this type the charge 

 is associated either with the oxygen or nitrogen atom, or with the group 

 as a whole, rather than with one of the hydrogen atoms. 



5. Ions of Abnormally High Conductance. Certain writers have 

 sought to relate the abnormally high conductance of the hydrogen and 

 hydroxyl ions with the fact that these ions are products of the ionization 

 of the solvent itself. 7 They have therefore adopted a theory founded 

 upon the old theory of Grotthuss, 8 according to which the mechanism of 

 the conduction process consists, not in a transfer of the ions through the 

 solution, but in an ordered arrangement of the polar molecules of the 

 electrolyte, alternately positive and negative, in accordance with the im- 

 pressed field. An interchange of positive and negative carriers takes 

 place between adjacent molecules resulting thus in a separation of the 

 products at the two electrodes. The work of Faraday and Hittorf has 

 definitely overthrown the theory of Grotthuss, but these later writers 



'Steele, Mclntosh and Archibald, Ztschr. f. phys. Chem. 55, 176 (1906). 



'Franklin and Kraus, Am. Chem. J. 23, 304 (1900); Franklin and Stafford, Am. 

 Chem. J. 28, 83 (1902) ; Franklin, Am. Chem. J. Jft, 285 (1912). 



6 Lucasse, Thesis, Clark Univ., 1920. 



T Danneel, Ztschr. f. Electroch. 11, 249 (1905) ; Hantzsch and Caldwell, Ztschr. f. 

 phys. Chem. 58, 575 (1907). 



8 Ann. d. Chim. 58, 54 (1806). 



