Did you know you could use the juice from a lemon to write a secret message? Materials: Instructions: STEP 1: Squeeze the lemon juice into the plate. STEP 2: Dip the cotton swab into the lemon juice.

Add Yahoo as a preferred source to see more of our stories on Google. William Abel, a mail censor at Iowa's State Prison, Fort Madison, using a hot iron to bring out a secret message written in lemon ...

A passport belonging to one of the Cambridge spies, a 110-year-old lemon used for invisible ink and a letter about the Queen's response to news of a Soviet agent in Buckingham Palace are among MI5 ...

When I was a kid, my friend had this pen with invisible ink. You could write a note with it and then the person you sent it to had a different pen that made the text show up. We though it was awesome ...

AUGUSTA, Ga. (WRDW/WAGT) - When we were kids, “invisible ink” meant lemon juice on notebook paper, write the message, and to see it someone would have to hold it up to the light for the words to ...