percussion cap
object, machine, apparatus, tool, technical instrument
A small cap at the rear end of a cartridge that is filled with a shock-sensitive explosive that detonates the propellant.
At the beginning of the 19th century, several inventors, including Alexander John Forsyth, Joshua Shaw, Joseph Egg and Samuel Johann Pauli, were working on the development of percussion-triggered cartridges.
Also known as a primer or percussion primer.
Traveljournal 1814