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XXVIII. On the Cause of Dissimilarity in the Phenomena 

 of the Ordinary and Voltaic Electric Fluids. By John 

 Goodman, M.R.C.S.L* 

 [" COMMENCED in the year 1840 a series of experiments 

 -*- on the identity of the fluids, voltaism and ordinary elec- 

 tricity. The conclusions at which I then arrived were detailed 

 in two papers read before the Royal Victoria Gallery of Man- 

 chester, and since published in the Annals of Electricity. My 

 attention was particularly directed to the subject of aqueous 

 decomposition, and the reasons why that produced by the or- 

 dinary electricity has failed to be identical with the voltaic in 

 the hands of the philosophers who have attempted the expe- 

 riments. After the many experiments which I have made in 

 this branch of the subject, both at that time and since, I find 

 that to effect decomposition it is necessary to make use of 

 platina poles of a magnitude in ratio *mith the quantity of fluid 

 circulating in the current; and to produce a pure elimination 

 of the gases, hydrogen at one pole and oxygen at the other, 

 the most material point to be attended to is the uniform, quiet 

 flowing of such current; that a perfect metallic union of all 

 parts of the circuit is necessary to prevent the occurrence of 

 accumulations (by solder or otherwise) ; that the oxide formed 

 upon copper wire, or even the lacquer upon other parts of the 

 apparatus, is sufficient to cause a break in the circuit, which 

 cannot be overcome without a given accumulation being ren- 

 dered necessary to overcome such break ; and that all accu- 

 mulations, from whatever source arising, as the sparks or col- 

 lections of fluid passing en masse from under the silken flap 

 to the receiving points, are sufficient to disturb the uniform 

 nature of the current, and to produce an admixture of the 

 gases by destroying the continually positive or negative con- 

 dition of the poles. 



I here exhibited an apparatus employed for the decomposi- 

 tion of water by the frictional electricity. The poles are of 

 fine platina wire exposed about the y^th of an inch. With 

 this apparatus I have frequently effected decomposition of 

 water, by the current alone, from the electrical machine. 



This experiment at once negatives the objections of Dr. 

 Faraday and other electricians to the analogy of this decom- 

 position with the voltaic "guarded poles" being no longer 

 employed. 



The phaenomena exhibited by the ordinary and voltaic elec- 

 tricities are in many respects widely dissimilar. To the former 



* Read before the members of the Manchester Institute of Natural and 

 Experimental Science, December 20, 1843 ; and now communicated by the 

 Author. 



