Hi Piggler, Glad to see you are out finding things! I realize it's not a valuable bottle but pontil era found in a surface dump is significant - that it sat untouched for such a long period of time AND did not fill with water, freeze and shatter is amazing.
These were medicine vials, inexpensive and mass-produced. Could have been any pharmacists concoction, either made to order or perhaps some standard remedy of the era.
Every dump is different - who knows what is or is not there.