MATRASS (mod. Lat. matracium), a glass vessel with a round or oval body and a long narrow neck, used in chemistry, &c., as a digester or distiller. The Florence flask of commerce is frequently used for this purpose. The word is possibly identical with an old name “matrass” (Fr. materas, matelas) for the bolt or quarrel of a cross-bow. If so, some identity of shape is the reason for the application of the word; “bolt-head” is also used as a name for the vessel. Another connexion is suggested with the Arabic matra, a leather bottle.