Write A letter with your own invisible ink!

You will need-

• A lime
• An old fountain pen
• A cup
• A sheet of white paper
• A source of heat.  Im using a candle

Method-

• Squeeze a lime and collect its juice in a cup.
• Dip the old pen into the juice and write out a secret letter. After writing 4-5 words dip the pen again.
• You cannot read what you have written.
• To read it, hold the letter close to a candle for a minute or so.
• The words will appear in a brownish colour.