I have 5 of these very small bottles, it appears they used to have cork stoppers? What were they used for? They are approximately 1 3/8" tall and approximately 3/8" across the bottom.
I have a few of those of varying sizes myself. After much research, I believe they naturopathic medicine vials. I believe mine to be early 20th century.
Definitely not Opium or the top would've been broke more. Kept it warm to dig it out.