Electricity in Electrolytes. 103 



aud ?i' negative ones respectively traverse the element of surface 

 in the positive^ and in the negative direction. 



9. In this conception of the condition of the liquid, the above- 

 mentioned difficulty disappears. It is at once seen that the in- 

 fluence exerted by the electric force upon the already existing, 

 though irregular molecular decompositions and motions com- 

 mences at once in the manner above described, and increases 

 with the intensity of the force instead of remaining ineffective 

 until the force has reached a certain limit of intensity. The 

 whole process, therefore, agrees very well with Ohm's law. 



Why the electric conductibility, which depends upon the faci- 

 lity with which the molecular decompositions take place within 

 the liquid, should be so different in different liquids ; why, for 

 example, these decompositions take place so much more readily 

 in the molecules of hydrated sulphuric acid than in those of 

 water ; and why the dilution of sulphuric acid should have so 

 remarkable an effect on its conductibility, — are questions which 

 certainly have not yet received satisfactory ausv/ers. Neverthe- 

 less, I see nothing therein which can be regarded as contradic- 

 tory to the foregoing theory. 



On the other hand, the increased conductibility in conductors 

 of the second class attendant upon an increase of temperature, is 

 explained very naturally by this theory ; for greater activity in 

 molecular motion will evidently tend to facilitate the mutual 

 decomposition of these molecules. 



By comparing the present theory with the former one of 

 Grotthuss, the principal difference will be found to consist in 

 the circumstance, that in the latter the molecular motions are 

 assumed to be originated by the electric force, and to take place 

 in two definite directions only, the decompositions progressing 

 regularly from molecule to molecule; whereas in the present 

 theory the motions which already exist arc merely modified, not 

 so as to become perfectly regular, but merely to such an extent 

 that in the great variety of motions which still exist the two de- 

 fiuite directions predominate. 



10. After I had committed to paper the foregoing view of the 

 deportment of electrolytic liquids, I learned from a conversation 

 with a cliemist, that similar views respecting the deportment of 

 compound liquid aud gaseous bodies had been already expressed 

 by "Williamson in a memoir on the Theory of the Formation of 

 iEthcr*. In this memoir we readf, "We are tluis forced to 

 admit, that, in an aggregate of molecules of any compound, 

 there is an exchange constantly going on between the elements 

 which are contained in it. For instance, a drop of hydrochloric 

 acid being supposed to be made up of a great number of mole- 



* Phil. Mag. November 1850, p. ;350. t Ibid. p. 355. 



