ELECTRICAL EFFECTS^ PRODUCED BY FRICTION- 205 



next on both sides j as does the wet cloth in the galvanic pile. 



But when the plates were entirely immersed up to the bars in 



the liquid, the latter being a conductor which embraced the 



whole, QWQTy difference between the metals in each intermediary 



pair was destroyed^ and the effect was reduced to that of one 



single pair. 



20. This will be shown by an analogous experiment, which, Apparatus to 

 r ii -r . ^ ,. , , imitate the 



tor another purpose, I made some years ago at Berhn, relatea phenomena 



in p. 253 of the 2d vol. of a work under the title of Traite o£ the eiec- 

 elementaire stir le Fluide electro-galvanique , published at Paris, 

 in 1804. I had then in view the phacnomenon of the electric 

 eel J that fish which produces the shock while in water. I tried 

 to imitate that eel by a galvanic pile, composed of 30 groups 

 of zinc and silver, separated by pieces of cloth imbued with 

 salt water. These groups were held together by 3 glass rods, 

 so kept together as to leave no projection outwards, and resem- 

 bling so far an electric eel. With this pile I made the follow- 

 ing experiments : — 1. It being held upright, I received a strong Experimentj. 

 shock ixovci \\. : having applied to it the \i^\ji?L\ glass tube with^^ ' *• 

 water, the oQ^^e^ were produced in that tube, 2. I laid the pile 

 on my table ; it continued to produce the shock. 3. I laid it in 

 a narrow wooden trough, with a little water at the bottom ; 

 the shock was less. 4. I poured successively more water into 

 the trough : in proportion as the water rose round the pile, the 

 shock was less j and at last, when the water covered it entirely, 

 not only there was no more shock, but, having applied be- 

 tween its extremities a glass tube with water, no gas was 

 produced. The electrical eel, therefore, has no perceptible ana- 

 logy with the galvanic pile, though the effects are similar. 



This, I think, will show Dr. Maycock the manner in which • 



his two experiments are reconciled with each other, and are 

 consistent with my theory. It will also give me much pleasure, 

 sir, if Dr. Maycock, finding any objections to my explanation, 

 will transmit them to me through your valuable Journal 3 for I 

 have a great regard for him, though not personally acquainted 

 with him. 



I have the honour to be. 

 Sir, 

 Your obedient, humble Servant, 



J. A. DE LUC. 

 Windsor, October the 5th, 1812. 



