A Body Warmer? Or Lighter?

The pharmacology developed by the ninja combined elements of science and chemistry. Astonishingly, the ninja invented a live coal that burnt for over 12 hours. This special ninja coal, called “do no hi”, could be hidden in the ninja’s clothing whilst still alight. It could also be used as a body warmer when camping out in winter or in other poor conditions to help the ninja withstand the cold. Charred Japanese paper, knotweed and eggplant stems were packed into a 15cm ventilated copper tube which had a cover so that it could be safely kept in the ninja’s clothing.

[do no hi]