The Oil of Saints is a substance, which is said to have flowed, or still flows, from the relics or burial places of certain Christian saints.
Sometimes the term refers to the oil in the lamps that burn before the shrines of saints or the water that flows from the wells near their burial places, or the oil and the water which have in some way come in contact with their relics. These oils are or have been used by the faithful, with the belief that they will cure bodily and spiritual ailments, not through any intrinsic power of their own, but through the intercession of the saints with whom the oils have some connection. In the days of the St. Paulinus of Nola (d. 431) the custom prevailed of pouring oil over the relics or reliquaries of martyrs and then gathering it in vases, sponges, or pieces of cloth. This oil, oleum martyris, was distributed among the faithful as a remedy against sickness [Paulini Nolani Carmen, XVIII, lines 38-40 and Carmen, XXI, lines 590-600, in Corpus Scriptorum Ecclesiasticorum Latinorum (Vienna, 1866 sq.), XXX, 98, 177]. According to the testimony of [Paulinus of Pétrigeux] (wrote about 470) in Gaul this custom was extended also to the relics of saints that did not die as martyrs, especially to the relics of St. Martin of Tours (Paulini Petricordiae Carmen de vita S. Martini, V, 101 sq. in Corpus Scriptorum Ecclesiasticorum Latinorum, XVI, 111). In their accounts of miracles, wrought through the application of oils of saints, the early ecclesiastical writers do not always state just what kind of oils of saints is meant. Thus St Augustine (City of God, Book XXII) mentions that a dead man was brought to life by the agency of the oil of St Stephen.
The Oil of St. Walburga
Famous among the oils of saints is the Oil of St. Walburga (Walburgis oleum). It flows from the stone slab and the surrounding metal plate on which rest the relics of St. Walburga in her church in Eichstädt in Bavaria. The fluid is caught in a silver cup, placed beneath the slab for that purpose, and is distributed among the faithful in small vials by the Sisters of St. Benedict, to whom the church belongs. A chemical analysis has shown that the fluid contains nothing but the ingredients of water. Though the origin of the fluid is probably due to natural causes, the fact that it came in contact with the relics of the saint justifies the practice of using it as a remedy against diseases of the body and the soul. Mention of the oil of St. Walburga is made as early as the ninth century by her biographer Wolfhard of Herrieden (Acta Sanctorum, Feb., III, 562-3 and "Mon. Germ. Script., " XV, 535 sq.).
The Oil of St. Menas
In 1905-1908, thousands of little flasks with the inscription: EULOGIA TOU AGIOU MENA (Remembrance of St. Menas), or the like were excavated by C.M. Kaufmann at Baumma (Karm Abum) in the desert of Mareotis, in the northern part of the Libyan desert. The present Bumma is the burial place of the Libyan martyr Menas, which during the fifth and perhaps the sixth century was one of the most famous pilgrimage places in the Christian world. The flasks of St. Menas were well known for a long time to archeologists, and had been found not only in Africa, but also in Spain, Italy, Dalmatia, France, and Russia, whither they had been brought by pilgrims from the shrine of Menas. Until the discoveries of Kaufmann, however, the flasks were supposed to have contained oil from the lamps that burned at the sepulchre of Menas. From various inscriptions on the flasks that were excavated by Kaufmann, it is certain that at least some, if not all, of them contained water from a holy well near the shrine of St. Menas, and were given as remembrances to the pilgrims. The so-called oil of St. Menas was therefore in reality, water from his holy well, which was used as a remedy against bodily and spiritual ailments.
The Oil of St. Nicholas of Myra
A fluid is said to emanate from the relics, of St. Nicholas of Myra preserved at Bari in Italy since 1087. It is said to have also flowed from his relics when they were still in Myra.
Other myroblytes or oil-producing saints
St. Gregory of Tours (De Gloria martyrum, xxx: Patrologia Latina, LXXI, 730) testifies that a certain substance like flour emanated from the sepulchre of John the Evangelist. The same Gregory writes (ibid., xxxi) that from the sepulchre of the Apostle St. Andrew at Patrae emanated manna in the form of flour and fragrant oil.
Following is a list of some of the other saints from whose relics or sepulchres oil is said to have flowed at certain times: