The answer
The cruets are two small bottles used to hold the wine and water for the Eucharist. They are mentioned in the list of gifts presented by Constantine to the churches of Rome.1252 There are three other cruets used by the Coptic Church. One is used to hold the Chrism (Myron oil) which can only be held by a priest or bishop. It is usually preserved in the Sanctuary and sometimes on the Altar.1253 The second is a cruet which contains the Ghalilaon oil (or Hagielaion) that is used in the Liturgy of Baptism. The third is a cruet that holds the oil that is used during the Apocalypse night on Bright Saturday when the book of Revelation (Apocalypse) is read in full. It is also used in the Liturgy of the Unction of the Sick, which is usually carried out on the last Friday of Lent. At the Coptic Church of St. Shenouda in Old Cairo, there is an ancient wooden box that is circular and has three round holes, which are probably for the three above-mentioned cruets.
Fr. Tadros Yacoub Malaty
Notes
1252 O. Burmester, The Egyptian or Coptic Church (Print Office of the French Institute of Oriental Archaeology, 1967).
1253 Hallett: p. 235.