to account for the PhcEnomena of Electricity. 34/ 



as eager to receive as the inside is to give out. During the pro- 

 gress of charging, both surfaces ought to manifest their cha- 

 racteristic properties in proportion as the charging increases. 

 Whether or not this is the case will be seen by the follovvins,' ex- 

 periments. The apparatus employed 'vas an insulated jar from 

 the stem of which projected a wire at right angles, and from 

 the outside coating another, two pith-balls being attached to 

 each by means of gilt thread. 



The jar, perfectly dry, is to be placed on the insulating stand, 

 and a chain is to be connected with the outside, so as to form 

 a communication with the ground. The electric machine being 

 in strong action, is made to pour in a stream of sparks until the 

 jar be fully charged. The chain being removed, the balls con- 

 nected with the inner surface will be repelled by excited sulphur, 

 and those with the outer surface will be attracted. If the inside 

 be now positive, why are the balls repelled by sulphur? and if 

 the outer surftvce be negative, why are its balls attracted ? 



If the jar be weakly charged, the results are as described by 

 Franklin, and it was no doubt on such that this philosopher 

 made his observations. But were the doctrine of accumulation 

 and deficiency well founded, the results should be the more de- 

 cided as the jar is more strongly charged. Yet when the hypo- 

 thesis supposes the jar to contain the greatest quantity of elec- 

 tricity, it is then that it evinces symptoms of containing the 

 least. 



The error does not relate merely to the surface occupied by 

 the accumulation. Let the jar with its wires, balls, &c. be set 

 on the stand as before, but not connected with the ground. 

 Let the jar be charged*, and while the cylinder is still turning 

 let the surfaces be examined : it will be found that excited sul- 

 phur repels the balls of both the inside and outside. This 

 cannot l)e explained while it is supposed that the outside is 

 then giving cut electricity, urged by the repulsion of the fluid 

 thrown in : for in this case if any body with a diminished quan- 

 tity, as sulphur, be presented, an attraction ought to follow. 

 When the charging is discontinued, another militating phaeno- 

 nienon occurs : tiie balls collapse, and after touching, again se- 

 parate, but with a different power, for they are now attracted 

 by excited snl]jhur. 



Here then are strong instances which oppose the Franklinian 

 hypothesis ; it appears that the supposed excess may evince the 

 symptoms of a state of diminution without anv abstraction having 

 taken place ; and the diminution may appear to be an excess 

 without any addition. Perhaps tlierc are on the whole no grounds 



* The wire on tlic outsirfe actint; as a (joint or as a communication with 

 the ground, aullcrs tbe chm-jjc to take place. 



for 



