Frictional Electricity

The word electricity is derived from the Greek word electron which means amber. In the sixth century BC, a Greek philosopher Thales found that when a piece of amber (a kind of resin) is rubbed with fur, it acquires a remarkable property; it attracts small pieces of leaves, cork or dust.

Today, we know that many other materials, such as hard rubber, nylon, plastic, sealing wax, etc. show the same effect. A substance which exhibits this effect is said to be electrified or charged.

You can see this kind of experiment by doing a simple experiment. On a dry day, place a few tiny pieces of paper on a table. Take a plastic ruler or comb and rub it with dry hair or a piece of wool and bring it near the pieces of paper. You will observe that the pieces of paper are attracted towards the rubber ruler or comb.

You may have experienced this attraction while combing your hair when dry or taking off a shirt made of synthetic fibre on a dry day. In each case, the object is charged by the rubbing process (i.e. by friction) and it is said to possess frictional or static electricity.

No significant advance was made in the understanding of the science of electricity until about AD 1600 when William Gilbert (1540-1603), a court physician to Queen Elizabeth I of England, undertook a detailed study of the kinds of material that would behave like amber. In his book De Magnate published in 1600, he gave the name electrica to substances like amber which when rubbed with suitable materials attracted tiny objects.