Thanks for posting. It would be interesting to know if the top of the mouth of the bottle (can you remove the cap?) is ground or not. The appearance of the threaded cap suggests to me an early style threaded closure as in very early 20th century.
Interestingly, this company bought out the very popular Sloan's Liniment brand in 1912. See https://baybottles.com/tag/pfeiffer-chemical-co/