g(^ ON THE ELECTRIC CCLLMN. 



of the column: and as also, in every group, the jon^er itself 

 serves only to separate the hinary groups oFzi/Jcarid copper, 

 the latter being in each of thenn on the side of B, this is 

 the negative extremity. The groups are contained between 

 three glass rods, covered with staling wax melted over them 

 while hot, and fixed in holes of the brass phites A, B, 

 where they have been introduced while the plates were hot, 

 and the holes filled with sealing wax. These brass plates 

 have in their lower part a pin, which enters freely into the 

 brass cap at the top of the pillars 1, 1. At the extremities 

 of the column are screws 3, 3, formed on the outside in the 

 shape of loops: they serve first, to press the groups between 

 the glass rods; and .besides to produce, by brass wires 

 hooked irj their loops, the communication of each extre- 

 mity with the nearest el^ctroscopey as represented in the 

 Jigure. 

 This column Jn general this column produces too great effects for the 



too poweruil experiments which [ have here in view, as the ffo/d leanes 



for some cxpe- \ '^ 



riments. Strike the sides of the electroscopes; while there should be 



merely a simple divergence: therefore, either a smaller co~ 

 lumn must be used, or the time must be chosen when tlie 

 600 groups produce only tliis eiTect. 

 Exp, 4, Exp. A. Having observed the actual quantity of diver- 



gence in both electroscopes, when 1 lay my finger on the 

 top of either of them, in order to produce the cpmniuriica- 

 tion of its extremity of the column with the ground, the 

 divergence ceases in it, and becomes nearly tlouble in the 

 Slow motion of other. Then taking off ray finger, and thus abandoning 

 thefluiddoes ^}^g column to its own operation, the diverg^ences are not 

 not take place . ,. , , i • p • 



inailcasei. immediately restored to their former quantity ; it requires 



some time to produce them again, even half an hour or au 

 hour. 



This shows a reluctance in the parts once possessed of the 

 electric Jiuid, to obey the cause which requires more of it 

 on ziuc than on copper, in order to estabiiyh the electric 

 equilibrium between tlnem. But this coiiCerns only tlie 

 quantity of electric Jluid, which the column possesses in 

 common with the surrounding bodies and the ambient air; 

 for at the same time thai this quantity delays to obey the 

 law of the colomn, if an insulated body, either positive or 



negative^ 



