the embossed lettering on the bottom of this small flask is very worn down. but all my research supports that it says SHELDON. The Historic Glass Bottle Identification & Information Website was VERY HELPFUL: [sha.org/bottle] particularly p.135 of this document: [sha.org/bottle/pdffiles/Sheldon-FosterGlass.pdf]
colorless glass 4.5" tall x 1.75" wide x 1" depth rectangular with a slight bend there is a raised rectangle on the concave side embossed above with "2 oz" ? deep uncentered side mold seams, discontinuous across the bottom & at the neck "mouth-blown" ~1" long round narrow neck flared prescription lip / flat top finish a small lip at the base of the concave side, possibly from the pattern dip mold or snap case
flaws: a large chip in the lip can be seen in pics, and a smaller one on the other side is barely noticeable. scratches and white fog from age.