^ Bt.ECTRtC EFfECtS Of FttlCtIO!*. 



gated more or less rapidly along their surface. Ghssi 

 though absolutely impenetrable to the electric matter (as I 

 have explained iu the preceding paper) permits the electric 

 fluid {i. e. electric matter united with vector] to move with a 

 sensible progress along its surface. 

 Efects of fric- 2. Friction excited between two bodies has no other effect 

 *'"**• than that of disturbing the natural equilibrium of the electric 



fluid, which tends always to be produced among all bodies 

 according to its aqjlual (but local, in u certain extent) quan- 

 tity on them and in the ambient air. If both the bodies, 

 which exerciseyric/iow on each other, are good conductors, 

 thisdisturbjince, the equilibrium being constantly restored, 

 is not perceived ; but if one has more disposition than the 

 other to attract the electric fluid thus agitated, with the fa- 

 culty of transmitting it to its remote parts ; when they are 

 separated, either suddenly, or in general before the equili- 

 brium of the fluid can be restored between them, one is found 

 /)0Ai7ii?^, as having acquired a proportional]quantity of electric 

 fluid greater than the ambient air, and the other negatixe, 

 as having lost that quantity ; both being supposed to have 

 previously possessed the same electric state as the ambient 

 air, 



3. The general effect therefore of friction between tws 

 l^odies is, that one never becomes positive, without the other 

 being made negative (or vice versa). This evident proof, 

 that all the electric phenomena which we are hitherto able to 

 produce at will, namely hy friction, proceed from the dis- 

 lurbance of the equilibrium of only one fluid, will be afforded 

 by the experiments, which I shall here relate after another 

 remark. 

 ^[egauTe and Mr. Cavallo, in his Complete Treatise on Electricity, (3d 



^*^'^' rt^iejof ^^**' ^^^* ^' P* ^^'^ ^^^ given a table containing the results of 

 different bo- his experiments of this kind, wherein is found, that certain 



di«s» but dif- |t>odle8 become either positive or negative, accordinsr to those 

 tertnt states of ^ ' o ' .-> 



thesamebody. by which \\\ey ^re rubbed. This circumstance had already 



shown, x\\t\\. negative and positive were not properties belong- 

 ing, lo cer!ain bodies, but only different states produced on 

 the same body by different circumstances, and in particular 

 by. tliQ difference of those which exercise friction on it : 

 Kow£ytfr>. there remained to be known what effect, in the 



latter 



