This is a tooled-lip Tincture of Iodine poison bottle. Back then seeing an image of Skull & Crossbones on something still filled people with fear, not romanticized images of pirates we think of nowadays.
Excavated all of this today:
From one tiny area I dug 34 clay marbles, 3 glass marbles, and several particularly round acorns and chestnuts (two of them pictured bottom left in the picture above). I can only imagine the acorns and chestnuts served as marble substitutes. Some were so round...
Got out late today just before sunset. Only managed to dig one bottle from the clay, but it was well worth it!
Here is the bottle in situ and immediately after extraction:
The clay preserved it very well for over 100 years. That's the trade off for digging in clay, the bottles are...