An Etymological Dictionary of the German Language/Büchse
Büchse, f., ‘box, pot, jar, rifle,’ from MidHG. bühse, ‘box, magic-box, firelock’; OHG. buhsa, from *buhsja, from Gr. πυξίς, ‘a box of boxwood (πύξος), medicine-box.’ The Gr. medical art was in vogue in the Middle Ages among all civilised nations, consequently some Gr. medical terms found their way into German. See Arzt, Pflaster. Comp. AS. and E. box, Ital. bossolo, Fr. bossette, ‘box.’