210 G.Th. Fechner's Justification of the 



the same manner if the same arrangement be observed. We 

 see therefore that De la Rive's experiment, in petroleum, ac- 

 cording to his account of it, could not succeed, either according 

 to the chemical theory, or according to the voltaic theory, and 

 that when it is all taken together, he proves nothing what- 

 ever. I succeeded however in varying these experiments so 

 that an argument may be drawn from them against the che- 

 mical theory. 



From the extreme vivacity with which the divergence took 

 place when the potassium attached to the condenser by means 

 of a platinum wire or even by direct contact (for in effect the 

 platinum is in this case quite unnecessary) stood in connection 

 with the earth by a moist conductor, and from the excessive 

 sensitiveness of the electrometer with a dry pile which I em- 

 ployed, it appeared to me not improbable, that even without 

 a condenser, by the contact of a negative metal with po- 

 tassium, a divergence would take place. If the brass point 

 from which the gold-leaf was suspended was brought into 

 contact either directly, or even with the interposition of an 

 air-dried strip of paper or linen, which appeared to conduct 

 much better than air-dried wood, with the platinum wire 

 of the potassium ball, whilst the latter was held immedi- 

 ately with the hand or by a slightly moistened slip of wood, 

 there might be perceived, when the gold-leaf had a certain 

 stability, a very weak, but undeniabjle, negative electrical di- 

 vergence ; and also a positive electrical one, if by reversing 

 the combination I held with my fingers the platinum wire, 

 and brought the electrometer with the intermediation of the 

 air-dried inter-conducter, or even only a layer of oxide which 

 had formed on the potassium, into contact with that metal. 

 From the numerous and varied experiments, sometimes bring- 

 ing the electrometer into contact with insulated, then uninsu- 

 lated platinum, 'without the agency of potassium^ I became 

 convinced, that in fact no divergence of the electrometer 

 would be produced by such contacts ; the contact of the po- 

 tassium was necessary ; similar counter-experiments have not 

 been neglected in the following. 



From the distinctness of the signs obtained (which as yet 

 do not afford any objection against the chemical theory) it 

 appeared to me not impossible, even by the entire insulation 

 of the potassium, to render signs of electricity perceptible, 

 and thus entirely to do away with the influence of moisture. 

 Under these circumstances, the condenser, for known reasons, 

 cannot be made use of; on the other hand, it is true that this 

 difficulty stood opposed even to the resultofthe application of an 



