ELECTRICAL FACTS. 
135 
can be made with the least probability of success respecting it. 
It seems proper that our enquiries and observations should be 
first directed to the simplest electric state of conductors} in 
the next place to electric charges, and lastly to excitation. 
Conductors of electricity may be considered in three points of Conductors, 
view ; 1 They afford a passage to the electric matter ; 2. They 
admit of a variation in the quantity of electricity they contain, 
and acquire by that means what is called a state of electricity ; 
3. And they admit of a variation in their capacity for retaining 
electricity, and by that means acquire an electric state, though 
the quantity of electricity they contain does not probably suffer 
any increase or diminition. This is, what is usually called, the 
electric charge, and perhaps depends entirely on the non-con- 
ductor, which, in all experiments, must surround or envelope the 
conductors made use of. 
Electricity parses from place to place, either invisibly Their nature, 
through or over conductors, or visibly along the surfaces of 
bodies. If a conductor be very small, in proportion to the 
quantity of electricity, it transmits the electricity visibly, 
whether its own substance be dissipated or not. Astronomical 
silver wire, of about the eight hundredth part of an inch thick, 
is very convenient for making experiments of this kind with 
small jars. Those bodies which are called non-conductors, do 
all conduct electricity, both invisibly and visibly; and it is 
known that this power resides at their surface, because glass 
balls charged and sealed up, retain their electricity for many 
years, and the -sealing does nothing more than destroy the con- 
nection between tire outer and inner surfaces. Hence it appears 
probable, that electricity is in almost every case, transmitted 
along the surfaces of bodies, and is not capable of flying ovet 
considerable intervals without such a surface to conduct it. But 
the sensation experienced in the electric shock, seems to shew 
that it can pass through the internal parts of conductors. 
From this conclusion we may conceive, how a non-conductor They proba- 
may become a better conductor at a certain density than at any biy act by sur- 
other.- Thus for example, dense air resists the passage 0 f^ aceou ^* 
electricity, because its particles are too close together to admit 
of free surfaces, without their being removed from each other, 
as is effected by the electric spark. If its rarity be greater the 
surfaces are more remote, and probably exert their conducting 
power 
