Carboy, demijohn or jimmyjohn, they all refer to glass containers. The name Carboy originated in Persia from the word; qarabah. Demijohn is French for; dame-jeanne, or Lady Jane from the 1600's. Demijohns are any glass vessel, with a large body, capable of holding from 5 and 16 gallons of liquid and with a small neck and generally encased in wicker. .