Rick,
That is a pre-fabricated privy liner. We have found about four of these.
They are late 1890' to early 1900's, and always have those types of bottles.....and they are hell to get out of the ground!
WOW! How much fun was that? Excellent vid but I cringed at the digger's lack of gloves and use of crude scratcher in that ancient glass. Tools with much more finesse have since been introduced, but hey, that was a few years back.