1876.] 



Mr. A. Tribe on Electrolysis. 



309 



middle or neutral point of the circuit, whether there be a series of de- 

 compositions and recompositions, or whether the particles from the 

 extreme points only are active, there must be a new combination of the 

 repelled matter." (Phil. Trans. 1807, p. 30.) 



The next enrichment of the subject was by Grotthus *, who contended 

 that since in the elementary combinations of the pile of Volta, as in a 

 magnet, there is polarity, it would establish a like condition in the 

 elements of water. 



Faraday, accepting the notion of polarity, added the necessary corol- 

 lary, the idea of the revolution of the molecules of the electrolyte t, which, 

 as far as I am aware, is the last important contribution to the theory of 

 the subject. 



If the condition of an electrolyte just prior to, and in the act of, de- 

 composition be in accordance with the views of Grotthus and Faraday, 

 as enunciated, an electrolyte may, it appears to me, be regarded as a 

 dielectric whose molecules are possessed of the power of mutually ex- 

 changing their constituents during discharge. This view, jointly with 

 some supposed points of resemblance between magnetic and electrolytic 

 substances to which it is unnecessary here to refer, led me to undertake 

 the experiments detailed in this communication. 



Experiment I. — A piece of thin copper wire about an inch long was 

 suspended lengthwise, by a piece of cotton, between the copper electrodes 

 (distant about 4 inches) of a Grove's battery +, and immersed in a 5-per- 

 cent, solution of potassium chloride. Gas was at once given off from 

 the end of the wire facing the positive pole, and after the lapse of 

 a few minutes the end facing the negative battery-pole was found 

 corroded. 



Experiment II. — Four small upright wooden posts 1 inch high were 

 fixed perpendicularly and 1 inch apart in a wooden stand 5 inches long. 

 Slits were made in the tops of these posts, and in them were inserted 

 strips of thin sheet silver. 



The whole arrangement, as in the figure, was then placed in a glass 

 vessel containing a 5-per cent, solution of copper sulphate mixed with a 

 little potassium chloride, the silver strips being arranged lengthwise in a 



* Ann. de Chimie, toI. lviii. p. 65. 



t Tyndall on Faraday, Proc. Roy. Inst. vol. v. p. 218. 



J Of ten cells both in this and all the other exp 3riments. 



