A French pharmacist's or medical doctor's jar for leeches or hirudines featuring a hand-blown glass footed bowl with raised lip opening.
The use of leeches in medicine dates as far back as Ancient Egypt. Leeches secrete an anticoagulant (known as hirudin) that prevents the clotting of blood. After being applied to the required site, they reduce the swelling in the tissues and promote healing by allowing fresh, oxygenated blood to reach the area.
If left open, leeches will crawl up the glass and escape, so leech jars had to have necks wide enough to extract the individual leeches but were often covered with muslin which was tied round the neck of the jar with string.
Leech jars are very uncommon - this is a rare find for the collector!