Now you can send a secret message!
What you'll need:
Orange, cup, paper, brush
Peel the orange and squeeze the SKIN. Put the juice in a cup.
Damp the brush with the juice and draw on paper.
Dry the paper until what you drew on it is rarely visible.
Put the paper up over an oven and see what you drew on the paper reappear in brownish color.
*Try this method to write a secret letter to your friend!