Military addenda from the Civil War (U.S.)'hardtack' a kind of dry hard biscuit for ship service and distribution to the embattled ranks. A more tender version survives and is popular in the here & now in 'laska as 'Pilot Bread':
Pvt. Right: "Drat and Tarnation, I just took a bite out of my hardtack and I found a soft spot!"
Pvt. Left: "What was it, a worm?"
Pvt. Right: "No, dammit, a &*^%%#@ nail!"
robo