Occam, my grandmother canned in glass jars. However, I think I missed something, because I’m not sure how canning and Napoleon’s armies relate, unless it is another term for “sacking" as in “sacking a city".
Ok Lois, a little history lesson, and BTW both my grandmothers and my mother in law canned veggies, fruits and meat in glass jars, especially pickled corn, beans and beets, a pleasant digression! Canning was invented to preserve food for Napoleon's army while on the march. His supply lines stretched back to France and were easily cut so canning would preserve food to serve his men and each soldier required at least three meals daily. His Grand Armee consisted of 600,000 men. You do the math here!. after the Napoleonic Wars canning spread to GB and America. Of course inventors in both countries were working on the concept as well, mainly for the navy.
Cap't Jack