Fun With Science

My son asked if we had any lemons.  He explained to me that he had read about using their juice as invisible ink.  We spent the next hour and a half writing secret messages with lemon juice and making hidden notes appear after holding the paper over a candle's flame.
It was great fun.
So much fun, in fact, that when my wife came home later, she and my son wrote another message on a piece of paper and held it over the candle flame to watch the writing magically appear.

Instead, the paper magically burst into flames.

I caught the mishap from the corner of my eye as my wife sat there staring at the fire in her hand.  My son screamed and jumped to the corner of the room where he rolled into a ball.  I thought it would best to grab the flaming paper from my wife and run with it like the Olympic torch through the house.   I was going to throw it in the kitchen sink.  I got about three feet before I dropped it on the carpet in fear of being burned.  This of course singed the carpet and panicked my son all the more.
Now I made a mad dash to the kitchen counter where I grabbed a glass of water and poured its contents on the flames.
We all stood silent for a moment over the wet, smoldering ashes.  There was a burn mark about the size of a cereal bowl in the center of the floor.  My wife shook her head and muttered, "What a three-ring circus".
After the mess was cleaned up (as best as possible) we shared a nervous laugh.
We concluded that our experiment had been a grand success.  We learned that stupid people tend to congregate together.