£i3 ON SOME ELECTRIC AL AND ELECTROCHEMICAL PHENOMENA. 



jRiirstrate tills or rounded terminations, attach to each extremity of this 

 **'"'*' rod a pair of pith balls, let the rod and its appendaj^es be 



represented by A — B. Presenttheextremity A to a positively 

 electrified surface, but not within its stiiking distance. Both 

 pairs of balls will open; and, if examined. A/ will be found 

 negative; B, positive. Remove the rod from the vicinity of 

 the electrified surface, the balls imrhediately collapse, and 

 5lo» electjioSy every electric sign ceases. A proof, that no electricity has 

 '^**tS*"'^^* t^^n communicated to it, and that the electrical appear- 

 ances produced arise only from the unequal distribution of 

 the natural electricity of the rod, during its approximation 

 to the electrified surface; seeing that, as soon as this cause 

 is removed, the effect it has produced immediately dis- 

 appears. 

 ExpejiEBMDt m If the preceding experiment be varied, by bringing any 

 -Bfciclithe part of A— B wit/tin the striking distance of the positive 

 cfijMaiEMku- surface, each pair of pith balls will open as before, but they 

 *'^' win be similarly electrified, being both positive ; and thiseffect 



(arising from com^ntmica^^rf electricity) will be permanent; 

 for, on removing the rod A — B from its proximity to the 

 electrified surface, the divarication of its balls will con- 

 tinue. 

 Tbesame term There are some variations of this experiment very import- 

 shMi(crm>tb= ant to electrical theory, but I mention here only the most 

 a{fip!?««iJo sins pie facts, as my intention is merely to show the impro- 

 *^*^^^S ct P''^^*y ^^ applying the same explanation to contrary and 



opposite efie^^ts. 

 Am electrified From what has been stated it will be evident, there are 



sarface may f^^^ methods by which an electrified surface may excite elec^. 



act 151 twd _ . . ' "^ 



wajs: trical effects in other bodies. 



fcy approKi- 1st. By approximation. In this case the electrified sur^ 



H]as!!.c.a, face loses wo w<? of its intensity, and the previously unelec^ 



tfified body becomes electrical only in consequence of the 

 vnequal distribution of its natural electricity. 

 fodbycom- 2nd. By direct communication. In this case the origi- 

 jfsmnicBEion. j,q| surface loses part of its intensity, and the body previously 

 unelectrified becomes electrical in consequence of an altera- 

 tion in the quantity of its natural electricity. 



The different effects of these two methods of electrificatioa 



A. 



