]£>0 INSTRUMENTS DISTINGUISHING ELECTRICITY 



tors, as the fimple fluid ; ftrongly attracting each other, and 

 not perceptible when combined in a due proportion ; capable 

 ot'exifting feparately at the confines of non-conductors in very 

 high condenfation ; caufing light and found when they ruth to- 

 gether through the fubftance of a conductor; and producing 

 the higheft temperature when they pafs through or meet in 

 non-conductors, &c. 

 Recording to the Without entering farther into thefc theories, or the additions 



theory of plus t j re q U i re i n order to (atisfy the facts, fuch as the attraction 

 and minus, that •> * ■> 



inftrument fuppofed to exift between conductors and the electric matter, the 

 which fhews the a tmofpheres of electricity, &c. the fubject of the prefent notice 

 «httinguUh the requires we lliould ufe the language of one of the two. The 

 courfe of cleftri- former is moft commonly adopted; and accordingly we fhoujd 

 fay that an inftrument which ihall diftinguifh the plus from the 

 minus ftate of electricity, will alfo (hew the current or direction 

 in which that matter is moved or carried. 

 Propofed means The fupporters of the theory called Franklin's, from the 

 •f doing this 5 name of the philofopher who invented or at leaft explained it 

 at an early period, have always been aware of the advantage it 

 would be to their fyftem if they could adduce any experiment 

 by which the direction of their electric fluid might be afcer- 

 tained. Dr. Franklin himfelf very modeftly offers conjectural 

 regions, why the one kind of electricity feemedtobe a redun- 

 from electric dancy and the other a deficiency, chiefly grounded on the lu- 

 ,lg ' ■ minous appearances at the extremity of the wires in the electric 



figure of the Hates. Henly likewife obferved the lights of the two electri- 

 fpark j cities in the figure of the fpark, of which the item is always at 



Lightning; the plus conductor and the ramifications at the negative ; fo 

 that the forked extremity of lightning will always denote the 

 receiving body, whether it be the cloud or the earth. He 

 exhaufted tube jalfo ufed his exhausted glafs tube with good fuccefs, as an in- 

 ftrument for the fame purpofe in which a receiving ball has a 

 luminous atmofphere, and a giving ball throws out ftreams of 

 flame of a candle; ijg^^ -phe fame philofopher firft noted, that the flame of a 

 fmall candle is blown towards a negative conductor, and from 

 a pofitive one ; though this experiment is not quite unequi- 

 vocal : And he made feveral other experiments which cannot 

 with coniiftent brevity be here detailed., having this leading 

 object in view. 

 Noneofthefeaf- Among the experiments made with this view, every one of 

 ford any deo an^ic-h, it m uft be confefled, leave the great queftion of the 



nature 



