Dr. Bourbon's Aromatic Forest Bitters Madison, Wis. (iron pontil)

Aqua cylinder with applied lip and iron pontil embossed "DR. BOURBON'S AROMATIC FOREST BITTERS CALWELL & Co MADISON, WIS." It is extremely rare and is one of just a few pontil marked bitters bottles from Wisconsin. This example is badly cracked but I am aware that there is at least one perfect one.