You have a Certo bottle I believe. It was gelatin used in canning, or making fruit fillings, jellies and jams, or something of this nature. I can't remember the exact use. It dates to the 1920's-1940's. Kelley
Yea...certo bottles look pretty cool...i have a couple that are a different color than yours...they came in many different colors. They are only worth about a buck or two though...