136 
ELECTRICAL FACTS. 
Doubt whe- 
ther conduc- 
tors attract 
electricity; 
The air main- 
tains electric 
intensity. 
Effect of 
pointed bo- 
dies. 
power better : and if the rarity be still greater, the leaf from 
one particle to another may be too great for the 'electricity to 
pass by the intensities we produce. The impermeability of a 
vacuum to electricity, seems strongly to countenance this 
doctrine. 
The next point of view in which conductors are to be con- 
sidered, relates to the electric state they are capable of. This is 
usually supposed to be a natural consequence of an attraction, 
exerted between the conductor and the electric matter ; but a 
more accurate view of the appearances will shew that this 
principle is by no means the leading agent in producing, or 
maintaining electric intensity, For the electric sparks a foot or 
more in length, scarcely ever strike the nearest part of the 
receiving ball, or pass by the nearest course ; pointed conductors 
emit or receive elect; icity, with the greatest facility j and 
no conductor retains its electric state in a common boylean 
vacuum. Since, therefore, it appears that conducting bodies 
exert a very inconsiderable force of at traction on the electric 
matter, it remains to be enquired, by what powers they retain 
the intensity they may be made to acquire. 
From the facility with which the electric matter traverses a 
vacuum, or ratified air, it is evident that the preservation of 
electric intensity in bodies depends greatly on the resistance 
afforded by dense air to its escape j but at the same time the 
phenomena of pointed bodies, shew that the co-operation of 
another circumstance is essentially necessary to the effect. 
What this circumstance is must be deduced from the solution 
of one of the most important, and most difficult, questions in 
electricity, that is to say, why do pointed bodies throw off, or 
receive electricity with the facility they are known to possess in 
this respect ? For the other question, why do blunt bodies retain 
electricity ? is the converse of this. 
The effects of pointed bodies have been accounted for in 
several ways, but the following are the most generally received. 
They who admit of electric atmospheres, shew that the atmos- 
phere surrounding an angular termination, admitting its altitude 
to be every where the same on a given conductor, is really larger 
than would be required to envelope the less prominent parts q { 
the surface, and thence they infer, that the escape or admission 
of electricity must be the easiest of all, at such terminations. 
This 
