A salt cellar (also called a salt, salt-box and a salt pig) is an article of tableware for holding and dispensing salt.
Use of salt cellars is documented as early as classical Rome. They continued to be used through the first half of the 20th century; however, usage began to decline with the introduction of free-flowing salt in 1911, and at last they have been almost entirely replaced by salt shakers. Tsk tsk.
Salt cellars were early collectibles as pieces of silver, pewter, glass, etc. After their role at the table was replaced by the shaker, salt cellars became a popular collectible in their own right.
Ours are cut glass, vintage, and each one is a little different. They're all sweet and approximately the same size.