1820.] Franklin's Theory of Electricity. 451 



has reached the centre of its atmosphere, as is shown in 

 figure 4. 



It is clear that this explanation of two electrified bodies is as 

 applicable to bodies deprived of the electric fluid, or negatively- 

 electrified, as to those in which there is an excess of electric 

 fluid, or which are positively electrified. 



The discoveries subsequent to the time of CEpinus having 

 furnished a satisfactory explanation of the repulsion of nega^ 

 lively electrified bodies, there is no reason to suppose with Haiiy 

 that negative repulsion is the stumbling block of Franklin's 

 theory, since (Epinus had given it an extension not sufficient 

 for the explanation of this phenomenon. The repulsion of nega- 

 tively electrified bodies being thus easily explained by Franklin's 

 theory, which has been demonstrated by Beccaria, according to 

 the aforesaid law, we may safely venture to set aside the exten- 

 sion which CEpinus has given it, and consequently cannot 

 deduce from it any argument against the theory of Franklin. 



Other phenomena have been observed during a discharge 

 from a glass jar, which might lead superficial observers to suppose 

 that the current of electric fluid which takes place whenever 

 electrified bodies are discharged is produced by two fluids which 

 unite from opposite sides. When, for example, one discharges 

 a bottle so slightly charged with fluid that only a little spark is 

 perceived, and the inner side of the bottle is touched with a 

 finger of one hand, and its outside with a finger of the other 

 hand, only a slight sensation is felt in the ends of the fingers. A 

 little stronger charge occasions a sensation all along the fingers. 

 On repeating this experiment with charges gradually stronger, 

 one feels more and more the passage of the fluid in the hands 

 and arms. 



Let the discharge be passed through a long series of metallic 

 globes, or other conductors, placed at very short but regular 

 intervals from each other (which may be determined by placing 

 a cord or other very thin substance between each, and after- 

 wards removing it), then on a faint discharge being made, one 

 may see the electric fluid pass only between the bodies nearest 

 to the two sides of the jar. Should the charge be increased but 

 ever so little, one sees the sparks pass between the bodies more 

 remote from the jar ; and the more the charge is increased, the 

 easier is it to discern the passage of the sparks between the 

 bodies still more remote from the latter. 



It is from these and similar phenomena that it has been 

 attempted to prove that during the discharge the electric fluid 

 proceeds from two opposite sides ; yet this cannot be inferred 

 from the above-noticed phenomena, as these explain themselves 

 very clearly, if, with regard to electrical effects, the least atten- 

 tion be paid to the three following well-confirmed observations : 



1. That the denser the electric current be which takes place 



2f2 



