in Magnetism and Electricity. 109 



ling-instruments. One part of the copper wire happened to be 

 placed in close proximity to the copper lightning-conductor of a 

 factory chimney, while another part of the same wire passed 

 within an inch or so of touching a thick iron gas-pipe connected, 

 of course, with the underground mains. The lightning, it would 

 seem, in its passage between the clouds and the earth, finding a 

 much easier path by way of the copper wire and gas mains than 

 by way of the lower extremity of the lightning-rod terminating 

 in the moist earth, melted and volatilized a length of about 15 

 feet of that portion of the copper wire which extended between 

 the lightning-conductor and the gas-pipe. 



207. Now the power which atmospheric electricity, or elec- 

 tricity of tension, possesses of effecting the electrolyzation of 

 water is so well established* that no reasonable doubt can be 

 entertained that the fusing of the copper wire in the instance 

 above mentioned was attended by the electrolyzation of the water 

 in contact with the metal gas mains, in the same manner as the 

 current from the 10-inch intensity-armature, which fused 3 feet 

 of iron wire at N also, simultaneously electrolyzed the water in 

 the pool. But in the case of the electrolyzation of water at the 

 lower extremity of a lightning-rod, the very foundation of any 

 mutual action which might be supposed to exist between the 

 positive and negative electrodes of an electromotor discharging 

 itself into the earth is entirely removed. 



208. Moreover, as the electrolyzation of the water in contact 

 with the inferior extremity of a lightning-conductor is indepen- 

 dent of the length of conductor extending upwards above the 

 surface of the earth, it would follow that if it were possible to 

 prolong this conductor through space to a planetary body (Mars, 

 for example) containing the same elecfrolyte as that forming 

 part of the terraqueous globe, or if such a line of metal were 

 extended between two aqueous spheres of planetary dimensions 

 (fig. 17), then would a current of electricity traversing this line 

 of metal (according to the polarity of the electrodes) transmute 

 the water of each of these spheres either into oxygen or into 

 hydrogen alone. 



209. Though I have been at considerable pains to prove ab- 

 solutely that the passage of an electric current from a conductor 



* M. Van Troostwyk, " Sur la resolution de l'eau en gaz oxygene et hy- 

 drogeue par l'etincelle electrique," Annates de Chimie, tome v. p. 276, 1790. 

 Barry, " On the Chemical Action of Atmospheric Electricity," Phil. Trans. 

 1831, p. 165. Faraday, "Electrochemical Decompositions by Common 

 Electricity," Phil. Trans. 1833, pp. 34-676. Andrews, " On the Polar 

 Decomposition of Water by Common and Atmospheric Electricity/' 

 British Association Report, 1855. 



