Invisible Ink

Globule wonders...

How can we make a picture appear on a piece of white paper?

Experiment: Invisible Ink

Material:

• A sheet of white paper per child
  
• A toothpick or a cotton swab per child
  
• 3.25% milk or lemon juice in a small bowl
  (many liquids can be used for invisible ink, see explanation below for other suggestions)
  
• A candle
  
• Cigarette lighter

Manipulations:

1. Trace an outline on a sheet of white paper using a toothpick or cotton swab soaked in milk or lemon juice.
   
   
2. Let dry. Your drawing will be completely invisible.
   
   
3. Your daycare worker will light the candle. **CAREFUL! You must remain calm and sit down once the flame is lit. Only adults can use lighters or matches.
   
   
4. One by one, your daycare worker will pass the drawings over the flame without burning them.
   
   
5. Watch closely, you will see the drawings appear like magic!
   

Explanation: Have you ever noticed how food becomes brownish when we cook it in a frying pan, oven, or toaster?

Food is made up of several nutriments (such as sugar and protein) which brown when heated. The same phenomenon occurred when your daycare worker passed the drawings over the flame.

With the heat, the sugars in the lemon juice and the proteins in the milk browned. There are many foods which can be used for invisible ink.

Here are a few you can try: juice from different types of fruit, onion juice, egg white diluted in water, vinegar, etc.

Have fun discovering other invisible inks!

Angélique Boissonneault

has a Bachelor's Degree in Biological Science. She has worked in a laboratory and tested her knowledge. She has taught Math, Chemistry, and Physics. She has also developed a simplistic and innovative approach designed to introduce young children to scientific experiments, old and new. She created her friend Globule. This character is sometimes red, and sometimes white. He guides little ones through their scientific experiments and discoveries. It is clear to see Angélique is passionate about children and science. Globule's Approach.