A matrass is a glass vessel with a round or oval body and a long narrow neck, used in chemistry

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

 as a digester or distiller. The Florence flask

Florence flask

A Florence flask is a type of flask used as an item of laboratory glassware. It can be used as a container to hold solutions of chemicals. A Florence flask has a round body with a single long neck and with either a round or a flat bottom...

 of commerce is frequently used for this purpose. The word is possibly identical with an old name matrass (Fr.

French language

French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

 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; bolthead is also used as a name for the vessel. Another connection is suggested with the Arabic

Arabic language

Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...

matra, a leather bottle.