Century-old LEMON used by German spy to send secret messages from Britain in invisible ink during WW1 goes on display
A 110-year-old lemon used by a German WW1 spy to send secret messages from Britain with invisible ink is going on display in ...
Secrets, spy tools and a 110-year-old lemon are on show in an exhibition from Britain's MI5
The lemon, now black and shriveled, helped convict Karl Muller, a German spy in Britain during World War I. It was found by ...