Encyclopædia Britannica, First Edition/Chewing-Balls

CHEWING-BALLS, a kind of balls made of asafœtida, liver of antimony, bay-wood, juniper-wood, and pellitory of Spain; which being dried in the sun, and wrapped in a linen-cloth, are tied to the bit of the bridle for the horse to chew: they create an appetite; and it is said, that balls of Venice treacle may be used in the same manner with good success.