336 Free Electricity. 
glass in a Leyden jar, that very little of the inductive influence 
can avail to produce an opposite state tending to neutralize the 
electrical excitement “to an equal amount.” 
opinion, that on account of the distance of thunder clouds from 
the earth, the electricity which they may acquire is too remote 
from the terrestrial surface to induce in this an opposite electrical 
state, capable of neutralizing the electricity of the cloud beyond 
a minute proportion. 
There seems to be an obvious means of discrimination between 
free and neutralized electricity, in the fact, that the one is asso- 
ciated with the surface of a conductor, so as to accompany it - 
when moved, while the neutralized electricity is inseparable from 
the superficies of the electric, through the intervention of which 
it exists. It is well known that the coatings of a pane or jar may 
be removed without disturbing the charge which may have been 
imparted by their presence. Yet if removed after the pane is 
fully saturated, each coating will hold a charge which it will give 
out in a spark to any uninsulated body, without any reference to 
the other coating which may meanwhile be remote and insulated 
from all communication with it. The spark thus yielded has the 
characteristics of free electricity. Having served as a part of the 
conductor, with which it had communicated, the coating is sur- 
charged in proportion to its capacity, and gives up the redundan- 
cy on communicating with the earth, without any reference to 
the other coating. The spark thus given I conceive to have the 
characteristics of free electricity. 
the case of electric accumulations in the atmosphere, there 
can be no substitute for the service performed by glass in Leyden 
charges but that which air can render ; and it can hardly be con- 
ceived that while agitated, as it is during thunder gusts, a stratum 
of that fluid can perform the part of a glass pane. 
