The items which are most durable as a form of currency (and are also the most portable) would most likely be olive oil. Olive oil has a long shelf time and doesn't require nor take up much space. It is very precious in lower quantities and is therefore a good currency.
In the early 1800s, stores weren't authorized to issue currency themselves.
Answer:
Trench Weapons.
Grenades.
Underground Mining.
Artillery and Mortars.
Machine-Guns.
Poison Gas.
Rifles.
Tanks and Armoured Vehicles.
