- Half a lemon
- Cotton bud
- White paper
- Lamp or other light bulb
To write your invisible message:
- Squeeze some lemon juice into the bowl and add a few drops of water. Mix them together.
- Dip the cotton bud into the mixture and write a message onto the white paper.
- Wait for the juice to dry so it becomes completely invisible.
- When you are ready to read your secret message or show it to someone else, heat the paper by holding it close to a light bulb.
For more information about how this works visit http://www.sciencekids.co.nz/experiments/invisibleink.html