370 EXPERIMENTAL INVESTIGATIONS. 



tries, and in electrolytes anterior respectively to discharge or 

 to electrolysis. 



Faraday observes, ' Experimental Researches/ 1164, 'In 

 an electrolyte induction is the first state, and decomposition 

 the second.' My present experiments show, I believe, that 

 in induction across gaseous dielectrics there is a commence- 

 ment, so to speak, of decomposition, a polar arrangement 

 not merely of the molecules, irrespective of their chemical 

 characters, but a chemical alternation of their forces, the 

 electro-negative element being determined or directed, though 

 not travelling in one direction, and the electro-positive in the 

 opposite direction. 



This arrangement is only evidenced at present, as it is in 

 electrolysis, by the action at the polar extremities or termini 

 of the dielectric ; possibly future researches may show, by 

 the action of polarised light, by magnetism or some other 

 means of analysis, that the polarity extends, as we theoreti- 

 cally believe it does, through the whole intervening matter. 



In the Experiment No. 5, with oxygen and excess of 

 nitrogen, reduction takes place by the effect of negative 

 electricity and heat ; at least there seems every reason from 

 analogy to believe that the effect of the nitrogen is only 

 negative, protecting the plate from oxygen, or at farthest 

 catalytic, aiding the reduction as sulphuric acid aids the elec- 

 trolysis of water. Upon the state of association of the gases 

 in what is generally called mixture I venture an opinion with 

 the greatest diffidence. I have always inclined to the opinion 

 that the difference between physical admixture, as it is termed, 

 of gases and chemical union, is one of degree, and the views 

 of Dalton ever presented to my mind grave difficulties. 1 * 

 My present results seem to me in favour of the chemical view, 

 as otherwise we can scarcely imagine electricity as effecting in 

 the instances given a merely physical separation ; it may, 

 indeed be said that there is composition and decomposition 

 produced by the same discharge, but this is very difficult to 

 conceive, and can hardly apply to the cases of oxygen with 

 nitrogen and of carbonic oxide. 



* Phil. Trans., 1843, p. 112. 



