Galvanic ^pparatus^ Theory of Galvanism, C^c. 289 



A piece of silvered paper about two inches square was folded 

 up, the metallic surface outward, and fastened into vices affixed 

 to the poles. Into each vice a wire was screwed at the same 

 time. The fluid generated by the apparatus was not perceptibly 

 conveyed by the silvered paper, as it did not prevent the wires 

 severally attached to the poles from decomposing water or pro- 

 ducing ignition by contact. 



In my memoir on my theory of galvanism I suggested, that the 

 decomposition of water, which Wollaston effected by mechanical 

 electricity, might not be tlie effect of divellent attraction like 

 those excited bv the poles of a voltaic pile, but of a meclianical 

 concussion, as when wires are dispersed by the discharge of an 

 electrical battery. In support of that opinion I will now observe, 

 that he could not prevent hydrogen and oxygen from being ex- 

 tricated at each wire, instead of hydrogen being given off only 

 at one, and oxygen at the other, as is invariably the case when 

 the voltaic pile is emploj'ed. That learned and ingenious phi- 

 losopher, in concluding his account of this celebrated experiment, 

 says, '•' but in fact the resemblance is not complete, for in every 

 way in which I liave tried it, I observed each wire gave out both 

 oxygen and hydrogen gas, instead of their beiaig formed separately 

 as by the electric pile." 



Is it not reasonable to suppose that an electrical shock may 

 dissipate any body into its elementary atoms, whether simple or 

 compound, so that no two particles would be left together which 

 can be separated by physical means ? 



Looking over Singer's Electricity, a recent and most able mo- 

 dern publication, I find that in the explosion of brass wire by an 

 electrical battery, the copper and zinc actually separated. He 

 says, page ISG, " Brass wire is sometimes decomposed by the 

 charge; the copper and zinc of which it is formed being sepa- 

 rated from each other, and appearing in their distinct metallic 

 colours." In the next page of the same work, I find that the 

 oxides of mercury and tin are reduced by electrical discharges. 

 *' Introduce," says the author, " some oxide of tin into a glass 

 tube, so that when the tube is laid horizontal, the oxide may 

 cover about half an inch of its lower internal surface. Tlace the 

 tube on the table of the universal discharger, and introduce the 

 pointed wires into its opposite ends, that the portion of oxide 

 may lie between them. Pass several strong charges in succession 

 through the tube, replacing the oxide in its situation, should it 

 be dispersed. If the charges are sutlicicntly powerful, a part of 

 the tube will soon be stained with metallic tin which has been 

 revived l)y the action of transmitted electricity." It cannot be 

 alleged that in such decompositions the divellent polar attractions 

 are exercised like those which characterize the action of wire 



Vol. 57. No. 27G. y^pril 1S21. O proceeding 



