[Sidenote: Liturgy of the Roman church.]
Pope Innocent I, writing to Decentius at the beginning of the fifth century, attributes the liturgy of the Roman church to St. Peter. It was first written in the fifth century; and Pope Vigilius sending it in 538 to Profuturus derives it from Apostolic tradition. The most ancient sacramentary or liturgical work extant of the Roman church is that of Gelasius who was Pope from 492 to 496[7]. He collected prayers composed by more ancient authors, and also composed some himself: and this Gelasian compilation was reformed by Gregory the Great and reduced to one volume[8], which may be considered as the prototype of our present liturgy. The canon or most solemn part of the mass has been preserved inviolate ever since, as appears from the Ordines Romani written shortly after the time of S. Gregory, and also from the explanations of it written by Florus and Amalarius. This canon as well as the order of prayer are the same as those of Gelasius, as Palmer observes (Orig. liturg. vol. 1, p. 119,) and are also nearly identical with those of the sacramentary of S. Leo. The Ambrosian and African liturgies also were evidently derived at a very remote period from that of Rome. From such considerations as these Mr. Palmer proves the very ancient or apostolical origin of the “main order”, the substance of the Roman liturgy. Origines liturg. vol. I, sect. VI. The author of the canon is unknown; yet we know the authors of some additions to the canon. Thus S. Leo I added sanctum sacrificium immaculatam hostiam, S. Gregory I, diesque nostros in tua pace disponas.
[Sidenote: Review of the ceremonies of the mass.]
[Sidenote: Mass of the catechumens, ambones, sermons.]
We shall not examine minutely all the prayers and ceremonies of the mass, or stop to enquire at what time and by what pope each of them was first introduced, lest we should weary the patience of our readers[9]; but we shall content ourselves with a general review of the mass, as it is now celebrated. We may divide it, as the ancients did, into two parts, the mass of the catechumens, and the mass of the faithful. The first part includes the preparation and confession