Invisible Ink for Writing Despatches.I like the idea of writing with a metaphorical inkwell in hand. Yes, that's an onion in the scout's non-writing hand, and a penknife and piece of onion on the ground.
Most scouts will be glad to know of a method of ensuring secrecy in the event of despatches falling into the enemy's hands. If the message is written in the juice of an onion and allowed to dry, it is then invisible to all unacquainted with the secret. When the despatch is warmed over a fire the writing stands out quite clearly.
In kidhood, under the influence of Clifford Hicks' novel Alvin's Secret Code, I wrote several despatches with lemon juice and toothpicks. HTML makes invisible writing even simpler — and there's no onion smell! See?