EXPERIMENTS ON THE ELECTRIC FILE.- 17& 



from one extremity to the other, and through the conductor 

 or chain of conductors which connects the two extremities : 

 but this ftream cannot take place in an infulated pile. From 

 this fingle distinction it appears, that the equality of the in- 

 tenfities of infulated piles affords no reafon to expect an 

 equality of the ilreams of the two piles when not infulated : 

 on the contrary, if the ftream meet with lefs impediment in a 

 large pile, than in one of fmaller diameter, the ftream will 

 produce a greater effect, in confequence of its greater velo- 

 city. 



To fee how far this velocity depended on the fize of the Effe&s of dif- 

 pieces of pafteboard employed, two piles were conftru&ed, *{lAozrlu 

 each of twelve pairs of the large plates, in one of which the 

 pafteboard was cut to the fize of the plates, in the other to 

 the diameter of half an inch only. The intenfities of both 

 were the fame, yet the other effects were much greater in the 

 pile with large pafteboards j for it gave very brilliant fparks, 

 which began with the fifth pair from the bottom, while the 

 Other pile fcarcely emitted any that were perceptible. On 

 making the pafteboards fomewhat larger than the metallic Thefe fcould not 

 plates, , the effect was by no means increafed, but rather e 00 arge: 

 diminifhed. It was found neceffary, likewife, that the pafte- and &ould be 

 boards in the large pile mould be well wetted. 



There is another apparent anomaly, however, in the effects Anomaly not ao 

 of piles differing in diameter : though the adion of the large gg*fefc 

 pile is fo much more powerful in fufing metals, not the leaft 

 difference can be perceived in the fhocks they give : and this 

 Dr. Van Marum confeffes is not accounted for by his hypo- 

 thefis. 



Some farther experiments were made refpe&ing the efficacy Solution of mu- 

 of the folution of muriate of ammonia, which was found to r5ate of ammo ~ 

 be preferable to common water, or to a folution of muriate of f or moiftenine 

 foda, for moiftening the cloth or pafteboard. A pile of twenty the cloths, 

 pairs with the ammoniac folution fufed into globules four 

 inches of wire, No. 16 ; while that with folution of common 

 fait did not fufe or even redden a fingle line, and that with 

 fimple water fhewed ftill lefs effed with regard to the fparks 

 it produced. 



As feveral authors have afcribed the greater effect pro- Not becaufe It 



duced by faline folutions to the oxidation of the metals, many ox ' ,dat r es *• me * 



. ■ A .,., . r . , . . J tals, for it is 



experiments were tried, with a view to alcertam this point, f a id to be Cups- 



N 2 by 



