510 Mv. Grove on the Electro-chemical Polarity of Gases. 



this particularly with bismuth, the flame attached itself to the 

 oxidated portion, aud then reduction immediately followed. Here, 

 as in all the electrical phsEnomena that I can call to mind, we 

 get the visible effects of electricity associated with physical 

 changes in the matter acting, changes of state in the terminals, 

 polarization of the intervening medium, or both*. These experi- 

 ments furnish additional arguments for the view which I have 

 long advocated, which regards electricity as force or motion, and 

 not as matter or a specific fluidt. 



The chemical polarity of gases shown, as I believe, in this 

 paper, associates itself with an experiment which I made known 

 in a lecture at the London Institution in the year 1843 J, and 

 Avhich was subsequently verified by Mr. Gassiot§ with more per- 

 fect apparatus than I possessed, viz. that when discs of zinc and 

 copper are closely approximated, but not brought in contact, 

 and then suddenly separated, effects of electrical tension are ex- 

 hibited, the one disc making the electroscope diverge with posi- 

 tive, aud the other with negative electricity, showing that the 

 effects ascribed by Volta to contact can be produced without con- 

 tact, and by mere approximation, the intei*mediate dielectric 

 being polarized, or a radiation analogous, if not identical, with 

 that which produces the images of Moser taking place from plate 

 to plate. 



The present experiments also associate themselves with the 

 gas battery, where, though an electrolyte is used as the means 

 of making the action continuous, or producing what is called 

 current electricity, the initiating effect is gaseous polarity, the 

 films of gas in contact with the respective plates of platinum 

 having antithetic chemical and electrical state . 



The results detailed in Experiment 13, appear to open a 

 new field of I'esearch. Priestley observed concentric circles pro- 

 duced by the electrical discharge from a powerful Leyden bat- 

 tery, which he describes as consisting of minute cavities and 

 globules of fused metal ||. In my experiments there is an alter- 

 nation of oxidation and I'eduction, a medium capable of producing 

 both being present ; the lateral effect and complementary colours 

 have to my mind something closely resembling the pha;nomena 

 of interference in light, although from the polar character of the 



* Gases at present believed to be elementary, probablj' undergo a quasi 

 chemical polarization by electricity ; thus portions of oxygen are changed 

 to ozone, &c. See a recent paper by MM. Fi-emy and E. Becquerel, 

 Comptes Rendus, Paris, March 15. [Phil. Mag. July 1852, p. 543.]— Note 

 added to the Proof, W. R. G. 



t Printed Lectm-e at the London Institution, 1842, p. 28. Con-elatiou 

 of Physical Forces, p. 48. 



X Literary Gazette, 1843, p. 39. § Phil. Mag., October 1844. 



II History of Electricity, 2nd edition, p. G24. 



