A A ON THE ELECTRIC COLUMN. 



between the effects of contact on the goU leaves of the eo- 

 Ivmn, and on the leaves of the mimosa sensitiva, and even 

 contact with different bodies. 

 Stronger proofs I come to greater symptouis of the motion of the electric 

 fluid '"*^^'"^ ^winf in the column, beginning by experiments, which will 

 prove what, in the former papet, I have concluded, from 

 my theory, namely, that by the cause assigned to this mo- 

 tion, the negative effect goes on increasing from the zinc to 

 the copper extremity of the column, at the same time that 

 the positive effect increases from the latter to the former ; 

 and that the electric state of each point of the i nsnlated column 

 is the sum of the correspondent terms of two inverse series 

 of progress represented by determined, though in some re- 

 spects variable, numbers, in a table given in that paper. 

 Addition to the For these experiments a third electroscope is used : in the 

 apparatus. Jigure it is seen connected with the middle point C of the 

 column, where is a thick brass plate with a projecting loop, 

 4. This immediate connexion of the electroscope with the 

 middle point of the column serves for some experiments; 

 but every other point of the column may be made to com- 

 municate with it, by the interposition of a soft wire held in 

 the middle by an insulating handle. When this is used, 

 the communication of the electroscope with the middle 

 point is taken off; and, by bending the wire, it is easily 

 made to connect, as conductor, xhe necessary parts of the 

 column with this electroscope. 

 Exp. 7. Exp. 7. At a time when there are simple divergences in 



the electroscopes at the extremities of the column, if they 

 be equal, positive at A, and negative at B, there is no di' 

 mergence in the electroscope at C; this is neutral; which is 

 the cassc expressed in Table I of the former paper: afad if 

 at this time any point of the column, at a distance from the 

 point C, on the negative or positive side, proportional to 

 one of the terms of the table, be tried with the insulated 

 conductor, the divergence which it produces will be found, 

 as exactly as can be expected in such experiments, cor- 

 respondent to the number expressed in the table, with its 

 sign. / 



5xp. 8- Exp. 8. In this situation of the column, the states ex- 



pressed in Table II and Table III may be abo observed 



by 



