from Ultimate Book of Kid Concoctions
2 T pure lemon juice
1. Pour lemon juice into a small glass or plastic dish.
2. Soak one end of the cotton swab in the lemon juice.
3. Use the lemon soaked end to write a secret message or draw a picture on a sheet of paper.
4. When you are ready to view your secret message, have an adult hold the sheet of paper near a light bulb or over a toaster. The heat source will slowly turn the lemon juice dark brown and reveal the message.
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