A container for the Blessed Sacrament. It was at first a small wooden box, usually round and with a lid. During the Middle Ages it was sometimes of metal or of ivory; when containing the Blessed Sacrament it was kept at first in people's houses, later in the sacristy, then on the altar, then suspended above the altar, sometimes inside a metal dove. When ambries, sacrament-houses, and tabernacles came into use for reserving the Blessed Sacrament, the pyx underwent a twofold development; by enlargement and the acquisition of a foot it developed into the ciborium by diminution in size and the addition of a hinged lid it became the small vessel now used for carrying a few consecrated hosts to the sick. Nowadays this is the meaning usually given to the word "pyx," though the name is used also for a similar vessel, a metal box that contains, inside the tabernacle, the large Host used for Benediction of the Blessed Sacrament.
Bibliography: j. braun, Das christliche Altargerät in seinem Sein und in seiner Entwicklung (Munich 1932). c. rohault de fleury, La Messe, 8 v. (Paris 1883–89) v.5.
[c. w. howell/eds.]
pyx / piks/ • n. 1. Christian Church the container in which the consecrated bread of the Eucharist is kept. 2. (in the UK) a box at the Royal Mint in which specimen gold and silver coins are deposited to be tested annually at the trial of the pyx.
In the UK, a pyx is also a box at the Royal Mint in which specimen gold and silver coins are deposited to be tested annually at the trial of the pyx by members of the Goldsmiths' Company.