fD6 Method of fitting iip Mr, De Luc's Electric ColumTit . 



nicnt acted sufficiently powerfully on a very delicate goUf-» 

 leaf electrometer, to cTYCourage me to iDake a row consist-" 

 ing ot a greater number of plates. To the two hundred f 

 added about three hundred more, usin^, instead oF the 

 Dutch meial, silver-leaF, and inserted the whole in a glais 

 tube luted up with brass caps, screw?, and balls* The 

 inslruuK'nt thus fitted up niiiy be called an Electric Rod, 

 1 have some of these rods with the plates not connected by 

 a string through then) ; wh'rch, provided the glass tube i* 

 very nearly ot the saoie diameter as the plates^ may be the 

 best way oF placing them ; but unless the tube fits accurately 

 the other mode will probably be found preferable, as the 

 plates can be more easily placed regubrly. 



The Dutch metal, or silver-leaf, may either be fastened 

 to the })aper with gmn> or paste made over the fire with 

 flour and water. 



The following experiments were made with a rod of five 

 hundred series of plates, — whether with the one ivi which 

 were two hundred plates of Duch metal, or in which there 

 was none, but silver-leaf instead^ it is not necessary to* 

 mention. 



2 1st Sept. I8O9. One leaf of an electrometer made of 

 Dutch metal kept flapping to and from the side of the 

 2;lass many times, when connected \\'\i\\ the electric rod. 



The ends of the rod being placed upon two* 



electrometers, — when the top of either of them vvastouched, 

 the electrometer at the opposite end diverged more imme-*- 

 diately, 



22d Sept. The rod was placed at the tfottom of an 

 electrometer ; one leaf was attracted to the side and flapped 

 several times. — This experiment shows that the electric^ 

 power of these piles or columns acts through a portion of 

 air : I held the upper part of the electrometer in my hand 

 during this experiment. 



24th Sept. A small piece of Dutch metal was attracted 

 up to the ball at the zinc pole of the rod, and adhered to it. 



4th Oct. A very light, ivory needle, turning on a point 

 (like a magnetic needle), was attracted by the rod ; when a 

 finger or a key was placed near one end of the needle, 

 and the ball at the en(l of the rod also near the same end 

 on the opposite side, the needle vibrated backwards and 

 forwards. The needle was insulated, I believe, by a piece of 

 anTiber. 



■ The needle, after having been touched by the 



silver-end pole, evidently receded from that pole; or, as it 

 is commonly called, was repelled, having been charged 



with 



