This afternoon, I found this bottle out in a woods that, 60 year’s ago, was an apple orchard. It’s about one and a half inches tall, and has a pink foam seal at the top, indicating that it once contained a liquid that was extracted with a syringe. On the bottom, in a within a rectangle, is the number 30. There is also a number 10 on the bottom.
Does anyone have any idea what substance would have been held within? Can the bottle be dated, given the information provided?