I found this on a site that sells antiques.
Quote- "The point or tip you see on the cap lifter was designed to aid in the removal of the Baltimore loop seal. The Baltimore loop seal was invented in the 1880's by William Painter and used into the 1900's. It was a small rubber seal used as a stopper on glass bottles which had a wire bail/loop extending out of it which required a tool to ease in the removal of the stopper" -end of quote.
That was part of the description attached to the item pictured below. Have you checked to see if yours unscrews to expose a corkscrew?