Explanation of the Effe& of the Ekaric Difcharge on Weter. 



349 



III. 



Experiments and Ohfervallom made -with the Vlenv of afcertaining the Nature of the Gax pr,- 

 duced by paff.ng EleElr.c Difcharges through JFater ; nvith a Defcription of the Apparatus for 

 thefe Experiments. By G£0JIG£ PEARSON, M. D. F. R. S. 



[ConcludeJ from page 248.] 



J- HE fire of the eleftric difcharge, in a very condenfed ftate, pafTes with inconceivable 

 velocity tlirough the whole length of the upper wire, in the cafe of the interrupted explofion, 

 p. 243-247. and of the fingle wire in the cafe of the complete explofion, p. 247, 248 ; fo that 

 It neither exerts its energy on the wire, nor on the water, lill it arrives at the extremity of the 

 wire. There it is momentarily interrupted and accumulated ; and, in the moment before 

 its diffufion through the water, it is fo denfe and in fuch quantity as to manifefl itfelf by a 

 fparlc at, or nearly in contact with, the extremity of the wire. In the moment of its dif- 

 fufion, a fmall part of this condenfed fire interpofes betwixt the conflituent elements of 

 the ultimate and invifible particles of water, that is, betwixt the hydrogen and oxygen, of 

 which water Is compounded, fo as to place them beyond the fphere of their chemical' at- 

 traction for one another ; and each ultimate particle of hydrogen and of oxygen uniting 

 with a determinate quantity of fire, new compound ultimate particles, confiRing of hydro, 

 gen and caloric, and of oxygen and ^caloric, that is, hydrogen gaz and oxygen gaz, are com- 

 pounded. This mode of adion of eledlric fire on water is confirmed by the efFed of 

 eledric fire and common fire, of a due degree of dcnfity, on o.xide of quickfilver, which is 

 by them refolved into oxygen gaz, and quickfilver in the vapour ftate. All calculation 

 muft needs be extremely vague ; yet, perhaps, fome elucidation will be obtained by con- 

 fidering that as it probably requires 70 or 80 thoufand difcharges to produce a cubic inch 

 of gaz from the fuppofed decompounded water, the gaz produced by each difcharge cannot 

 amount to one 2oo,ooodth of a grain weight. The quantity of condenfed fire at the ex- 

 tremity of the wire mud be immenfely great, comparatively with the quantity of it which 

 enters into the compofition of the gazes from decompounded water ; otherwife it is not 

 eafy to conceive how even the minuteft particle of water could be decompounded the 

 eledric fire being in contad with a large body of water, and paffing through it with a ve- 

 locity which is incalculable. 



The reafon of the metal wire not uniting to the oxygen of the decompounded water as 

 in the experiment of paffing water through red-hot iron tubes, might be alfigned from 'the 

 intenfity of the fire only ; but it is alfo on account of the rapid motion of the difcharge as 

 well as, partly, from the great quantity of light. In a very low temperature, light deco'i 

 pounds oxide of filver, and of fcveral other metals ; alfo oxy-muriatic acid, nitric acid S. 

 Hence light both decompounds bodies, and prevents oxygen from coming within the fphc 

 of chemical attradion of the metal. 



It is fuppofed that but a very minute proportion indeed, of the elcdric difcharge, is 

 confumcd at the en.l of the wire in the compofition of gazes, during a momentary inter- 

 ruption, as above fai.l ; for it diffufcs itfclf through the water, between the wires, yieldinir 

 a volume of vivid light, till it arrives at the extremity of the under wire or point of the 



convexity 



;l. Sec. 



