The Secret Letter

Did you ever write an invisible letter using lemon juice?  After watching Diego check the mailbox again today without finding a response to his letter, I realized that I'd better send him something very special.  I remember doing this with my brothers when we were kids and finding it a terrific thrill.

Just assembling the materials tonight felt magical.

I don't remember ever writing an invisible letter with a brush by candlelight, but it was such a delight that I can't believe I waited this long!

All you have to do is write your letter with lemon juice and let it dry.  To make it visible, have an adult wave the paper over a flame (candle, stove, lighter), letting the flame almost burn the paper.  The areas where you applied the lemon juice will brown faster than the rest of the paper, the words will slowly appear, and you will have decoded the secret message.

Of course, I did a test:

I know that this will be so exciting for Diego tomorrow.  I'm sure any child who has never seen this before  will be totally enchanted by it, so go get out your brush and lemon and write someone a secret letter!