Wisconsin State Agricultural Society. 
99 
place, but also of the electrified body; (4) the length of the body in 
which electricity is induced, and (5) the perfection of the point pre¬ 
sented, which has great intensity of action and tendency to open a 
passage through the air for the electric fluids. 
This inductive action takes place at a great distance, not only 
through the air, but through any intervening non-conductor. 
Thunder-clouds are sometimes so highly charged that a discharge 
takes place through an intervening distance of miles. 
DYNAMICAL ELECTRICITY. 
The phenomena of frictional electricity in motion , in consequence 
of its great velocity, are very difficult to investigate. The mechan¬ 
ical effects due to this agent are produced by it while in motion. 
In a state of equilibrium it seems to produce no effect upon the bod¬ 
ies in which it is accumulated. It is only when it passes explo¬ 
sively from a charged bod}', that mechanical effects are observed. 
Electricity which is developed by chemical action is so different in 
kind from frictional electricity, that we are not warranted in rea¬ 
soning by analogy, as some do, from one to the other. Frictional 
electricity is of much higher tension, showing a repulsive force be¬ 
tween the particles of the fluids which does not seem to exist in 
galvanism. 
The limits of this paper will allow us merely to state the leading 
phenomena of Dynamical Electricity which bear upon our subject. 
1. When a discharge takes place between a cloud or other elec¬ 
trified body and the Earth, the fluid will always follow the line of 
least resistance. Of several conductors equally good, it will take 
the most direct. It may follow a circuitous path in preference to 
the direct, if the former is a better conductor. Lightning often 
seems to pursue a very fitful course in passing through a building, 
but it is always determined by the general fact just stated. 
2. In the transmission of electricity through a conductor of suf¬ 
ficient size, the fluid passes on or just beneath the surface. In this 
respect it differs from galvanic electricity, which pervades the whole 
mass of the conductor. If the charge be very large compared with 
the conductor it may pervade the whole mass, in which case the con¬ 
ductor is generally dissipated or destroyed. That frictional electricity 
in passing through an adequate conductor is confined to the portion 
