Pickled lime

Pickled lime is a food that involves the pickling of limes to preserve them and add flavor. In the 19th and early 20th centuries, pickled limes were exported from the West Indies to areas in the Northeastern United States. In the mid-19th century, pickled limes were in demand in New York, and by the late 19th century they were mostly exported to Boston. During this time period, stores would display them in glass jars atop counters and sell them by the piece. Some customers purchased entire barrels of them at a time. During the mid-19th century, pickled Key limes were exported from Florida to Boston.

Source: Wikipedia