Experiments and Observations on Electricity
Benjamin Franklin 1748
- All objects contain a substance called an electric fire
or electricity. The total amount of this substance in the world is a
- Rubbing together of two objects results in the transfer
of electricity from one object to the other. + means a gain in
electricity, - means a loss. Glass becomes electrified or gains positive
when rubbed with silk.
- Two objects electrified in the same sense, + and + or -
and -, exert repulsive forces on each other. Two objects electrified
in the opposite sense, + and -, exert attractive forces on each other.
- The mutual forces due to electrification are increased if
the amount of electrification is increased or if the objects are brought
closer to each other.
- Some materials (conductors) readily conduct electricity
whereas others (insulators) do not.