Relative Intensities of Elementary Voltaic Actions, 43 



or weaker, is at once referrible to the condition and force of 

 the chemical affinities which are brought into action, and may, 

 both in principle and practice, be considered as perfectly di- 

 stinct from any other mode. 



909. The direct reference which is thus experimentally 

 made in the simple voltaic circle of the intensity of the electric 

 current to the intensity of the chemical action going on at the 

 place where the existence and direction of the current is de- 

 termined, leads to the conclusion that by using selected bodies, 

 as fused chlorides, salts, solutions of acids, &c., which may 

 act upon the metals employed with different degrees of che- 

 mical force ; and using also metals in association with platina, 

 or with each other, which shall differ in the degree of chemi- 

 cal action exerted between them and the exciting fluid or elec- 

 trolyte, we should be able to obtain a series of comparatively 

 constant effects due to electric currents of different intensities, 

 which would serve to assist in the construction of a scale so 

 as to supply the means of determining relative degrees of in- 

 tensity accurately in future researches. 



910. I have already expressed the view which I take of the 

 decomposition in the experimental place, as being the direct 

 consequence of the superior exertion at some other spot of the 

 same kind of power as that to be overcome, and therefore as 

 the result of an antagonism of forces of the same nature (891. 

 904.). Those at the place of decomposition have a reaction 

 upon, and a power over, the exerting or determining set pro- 

 portionate to what is needful to overcome their own power ; 

 and hence a curious result of resistance offered by decomposi- 

 tions to the original determining force, and consequently to the 

 current. This is well shown in the cases where such bodies 

 as chloride of lead, iodide of lead, and water would not de- 

 compose with the current produced by a single pair of zinc 

 and platina plates in sulphuric acid (903.), although they 

 would with a current of higher intei)sity produced by stronger 

 chemical powers. In such cases no sensible portion of the 

 current passes (967.); the action is stopped : and I am now of 

 opinion that in the case of the law of conduction which I de- 

 scribed in the Fourth Series of these Researches (413.*), the 

 bodies which are electrolytes in the fluid state cease to be such 

 in the solid form, because the attractions of the particles by 

 which they are retained in combination and in their relative 

 position, are then too powerful for the electric current. The 

 particles retain their places; and as decomposition is prevent- 



[* An abstract of Mr. Farada}'*s Fourth Series, stating the nature of the 

 law of conduction in question, was given in Lond. and Edin. Phil. Mag., 

 vol.iii. pp.449, 450.— Edit.] 



G2 



