Pounce box
Pounce boxes are containers with perforated heads used to hold and discharge a fine powder made of sand or pounce (pulverized gum sandarac). When shaken onto freshly written documents, the powder stops the ink from running. Pounce boxes were considered essential elements of writing equipage in the eighteenth century. According to family legend, George Washington used this particular example during the Revolutionary War.
Published References"Gen. Washington's Sand Box," c. 1897, Curatorial File, W-548, MVLA.