"Perfect Seal Widemouth adjustable" jar

I have recently went on a camping trip with a friend and about half a Km into the bush off of a power line in Ontario, Canada, we stumbled upon a bunch of rusty cans. we dug out a bit of the cans and found half of a bottle buried under the ground, we then proceeded to uncover about 10 more bottles, and even one with a rusted lid with unidentified powder in it. some are in very good condition with rusted lids and some have a little crack.

Poor