468 On the Conductibility of Liquids for Electricity. 



galvanometer, and the needles remained at rest. But when this 

 wire was removed after the establishment of the communication 

 with the pile, we saio the galvanometer deviate instantly in an 

 opposite direction to the deviation produced by the induced current 

 of the preceding experiment, and rest, after a few oscillations, at 

 10°. By replacing the wire, then interrupting the circuit and 

 again removing the wire, we saw the galvanometer deviate in the 

 contrary direction, and rest, in the same manner, at about 10° on 

 the other side of the divided arc. In both cases the deviation 

 diminished regularly by little and little until it became 0° ; we 

 did not exactly measui*e the time which this occupied, but it 

 appeared to us to be about 30 or 40 seconds. 



These experiments were frequently repeated, and always with 

 the same result. We need not say that we always took the 

 precautions pointed out by you, to prevent the eiffect of an induc- 

 tion in one of the metallic conductors. 



Polarization therefore takes place in the electrodes which 

 serve, not only to convey a current into a liquid, but to carry out 

 the current induced in the liquid itself. It appears to us that this 

 fact directly contradicts the theory which attributes polarization 

 to an accumulation of the two electricities upon or around the 

 electrodes ; for in the present case not only would such an accu- 

 mulation be infinitely less probable than in ordinary cases of 

 polarization, but if it existed, it would necessarily give rise to a 

 current not in a direction opposed to that of the principal 

 current, but in the same direction. 



May we therefore regard all polarization as an effect of elec- 

 trolytic decomposition, and consequently as an irrefragable proof 

 of the existence of this decomposition ? If this be true, we shall 

 be led to regard the opinion of those who admit the possibility 

 of the transmission of a current, or of a portion of a current 

 through a decomposable fluid without the occurrence of any 

 decomposition, as resting upon very slight grounds. Whenever 

 we have passed a current, however weak, through such a liquid, 

 we have always observed an undoubted polarization of the elec- 

 trodes. 



We shall take the liberty to describe one other experiment, 

 which is still more convincing in this respect than that described 

 at the commencement of this communication. We immersed 

 two plates of platinum, 6 centimetres in length and 5 centimetres 

 in breadth, at a distance of about 1 centimetre from each other, 

 in distilled water. One of these plates communicated with the 

 ground by a metal wire; they had previously been carefully 

 cleaned by heating to redness, and consequently, when put in 

 communication with the galvanometer, did not produce any 

 sensible deviation. But as soon as a single spark from a common 



