Hi;
don't have a clue about this bottle, but was told that it was a bitters bottle by the digger that I got it from. Just about 13" tall, and about 4" in diameter at the base.
The elderly gentleman that I got this from thought it was a Brown's Indian Girl Bitters bottle, but it isn't. The ONLY marks on it are "J & M G" with no other punctuation. Bottle is 13" tall and 4" wide at it's base.Photos below.