350 Experimental Researches in Electricity, 



through the discharging train, Faraday obtained the am- 

 plest evidence of the chemical influence of the current. Sul- 

 phate of copper, iodide of potassium, sulphate of soda, &c. 

 &c. were rapidly decomposed, so that no doubt could re- 

 main that voltaic and ordinary electricity had power of 

 chemical decomposition alike in their nature, and governed 

 by the same law of arrangement. 



Atmospheric electricity being admitted universally to be 

 of the same nature as ordinary electricity, instances of che- 

 mical decomposition by the former, furnish proofs of a like 

 power belonging to the latter. Of these Faraday alludes to 

 several, and especially to an experiment by Mr. Barry, in 

 which two tubes, having wires passing through each closed 

 end, as is common for voltaic decompositions, were employ- 

 ed. The tubes were filled with solution of sulphate of 

 soda, coloured with syrup of violets, and connected by a 

 portion of the same solution in the ordinary manner ; the 

 wire in one tube was connected by a gilt thread with the 

 string of an insulated electrical kite, and the wire in the other 

 tube by a similar gilt thread with the ground. Hydrogen 

 soon appeared in the tube connected with the kite, and 

 oxygen in the other, and in ten minutes the liquid in the 

 first tube was green from the alkali evolved, and that in the 

 other red, from the free acid produced. There are several 

 doubtful points connected with this experiment, some of its 

 details being with difficulty reconcilable with others ; and 

 Faraday remarks of it, " Mr. Barry's experiment is a very 

 important one to repeat and verify. If confirmed, it will 

 be, as far as I am aware, the first recorded case of true 

 electro-chemical decomposition of water by common electri- 

 city, and it will supply a form of electrical current, which, 

 both in quantity and intensity, is exactly intermediate with 

 those of the common electrical machine and the voltaic pile." 



With regard to magneto-electricity, the next form that 

 comes under notice, the experimental effects obtained by it, 



