Equipment:
- Lemon
- Water
- Small plate
- Toothpick
- White paper
- Lamp
Method:
Squeeze the lemon juice into a plate, along with a few drops of water and mix using the spoon.
Dip a toothpick into the mixture.
Write a secret message on the white sheet of paper using the toothpick.
When the page is dry the writing will be invisible.
Hold the paper over a lamp to heat it and watch how the invisible writing will slowly turn brown!
