Observations on some Experiments in Electricity. 65 
Some authors have represented that the outer sheet next to the 
‘negative ball, would be found more aos torn than that to which 
the positive should be applied. 
This has not been verified by my experiments when the balls were 
of equal size. In performing the experiment on sixty sheets of letter 
paper, it was observed that several of the outer sheets on each side, 
were torn from the point of contact as a centre, in radiant lines about 
half an inch in length. But the separate points of paper did not all, 
on either side of the package, appear to be throws outwards. 
one side of the hole they seemed to have been dashed into the cavity, 
and on the other, were inclined upwards around the center. As the 
smallest of the perforations was about one-tenth of an inch in dia- 
meter, it was ‘easy to distinguish that every sheet partook of the double 
protrusion described by Symmer. The coyprses of the opposing cur- 
rents were not always found to be two parallel straight lines, but ra- 
ther indicated a double spiral, like two strands of a cor 
%. The Card between the two Poles. 
In repeating the experiment of Mr. Lullin upon a card covered 
with vermillion, and interposed between the two wires from a battery, 
so that one of the latter should touch each of its faces, the usual result 
was obtained, of forming a black streak upon the colored surface 
from the positive, to a point opposite to the negative wire, where a 
hole was perforated, with a burr protruded, on both sides of the pa- 
per. On varying the experiment according to the method of Tre- 
mery, by placing the card in vacuo, and using small wires for the two 
poles, similar perforations, ten or twelve in number and in a line, 
more than three quarters of an inch in length, were produced at a 
single discharge. This line occupied the whole distance between 
the positions of the two opposite wires. In other instances, the dis- 
tance being increased to several inches, the perforations were less 
numerous, commonly no more than one or two, and were found at 
intermediate points between the two poles, but did not as sometimes 
represented, show any decided relation between the degree of ex- 
haustion, and the distance from the negative wire. It is evident from 
these facts, that the point of rupture in vacud is a matter dependent 
chiefly on the accidental weakness of the paper at one point more 
‘than at another. For if the card be strong, but not very wide, the 
electricity will sometimes take a circuit over the edge, instead of fol- 
lowing the direct path and passing shone? the paper. This result 
Vor. XXV.—No. 1. 
