Chemistry Invisible Ink Lab History

Teach physical and chemical change thru the science of “steganography” in this easy-to-implement yet highly engaging lab. No chemistry experience is required. However, this lab is a great addition to working with your history department to make the Revolutionary War come alive. George Washington used this technique to send coded messages throughout the war. Students will discover that the juice of lemons contains carbon which will enable them to write a secret message in the same manner as the Continental Army did in the 1770s.

MATERIALS
½ Lemon
Saucer
Water
Teaspoon
Cotton swab
White paper
Lamp (any heat source)