Important Topics

1. Positive and negative changes. Law of electric action.

2. Electroscope and its uses.

3. Conductors and insulators.

Exercises

1. Is air a conductor? Give reasons for your answer.

2. Mention two points of likeness and two points of difference between magnetism and electrification.

3. If you were testing the electrification of a body with a charged pith ball suspended by a silk thread, would attraction or repulsion be the better test? Give reasons.

4. Have you ever produced electrification by friction outside of a laboratory? Explain.