MASS, in Mechanics, the matter of any body cohering with it, that is, moving and gravitating along with it. In this sense mass is distinguished from bulk or volume, which is the expansion of a body in length, breadth, and thickness. The mass of any body is rightly estimated by its weight; and the masses of two bodies of the same weight are in the reciprocal ratio of their bulks.

Mass, Missa, in the church of Rome, means the office or prayers used at the celebration of the eucharist; or, in other words, in consecrating the bread and wine into the body and blood of Christ, and offering them so transubstantiated as an expiatory sacrifice for the living and the dead. As the mass is in general believed to be a representation of the passion of our blessed Saviour, so every action of the priest, and every particular part of the service, is supposed to allude to the particular circumstances of his passion and death.

Nico, after Baronius, observes that the word missa comes from the Hebrew missach, oblatum, or from the Latin missa, missorum, because in former times the catechumens and excommunicated persons were sent out of the [7:14:302] church when the deacons said Ite, missa est, after sermon and reading of the epistle and gospel; they not being allowed to assist at the consecration. Menage derives the word from missio, dismissing; and others from missa, missing, sending, because in the mass the prayers of men on earth are sent up to heaven.

The general division of masses consists of high and low. The first is that which is sung by the choristers, and celebrated with the assistance of a deacon and sub-deacon; low masses are those in which the prayers are barely rehearsed without singing.

There are many different or occasional masses in the Latin church, some of which have nothing peculiar but the name; such as the masses of the saints; that of St Mary of the snow, celebrated on the fifth of August; that of St Margaret, patroness of lying-in women; that of the feast of St John the Baptist, at which are said three masses; that of the innocents, at which the Gloria in excelsis and the Alleluia are omitted, and, it being a day of mourning, the altar is of a violet colour. As to ordinary masses, some are said for the dead. At these masses the altar is put in mourning, and the only decorations are a cross in the middle of six yellow wax-lights; the dress of the celebrant and the mass-book are black; many parts of the office are omitted, and the people are dismissed without the benediction. If the mass be said for a person distinguished by his rank or virtues, it is followed with a funeral oration. They erect a chapelle ardente, that is, a representation of the deceased with branches and tapers of yellow wax, either in the middle of the church or near the tomb of the deceased, where the priest pronounces a solemn absolution of the deceased. There are likewise private masses said for stolen or strayed goods or cattle, for health, for travellers, &c. which go under the name of votive masses. There is still a further distinction of masses, which are denominated from the countries in which they were used. Thus the Gothic mass, or Missa Mosarabum, is that which was used amongst the Goths when they were masters of Spain, and is still kept up at Toledo and Salamanca; the Ambrosian mass is that composed by St Ambrose, and used only at Milan, of which city he was bishop; the Gallic mass is that used by the ancient Gauls; and the Roman mass is the one used by almost all the churches in the communion of the Roman Catholic church.

Mass of the Presanctified (Missa Praesanctĳicatorum) is a mass peculiar to the Greek church, in which there is no consecration of the elements; but, after singing some hymns, they receive the bread and wine which was before consecrated. This mass is performed during the whole of Lent, excepting on Saturdays, Sundays, and the Annunciation. The priest counts upon his fingers the days of the ensuing week on which it is to be celebrated; cuts off as many pieces of bread at the altar as he is to say masses; and after having consecrated them, steeps them in wine, and then puts them in a box, out of which, upon every occasion, he takes a portion with a spoon, and putting it on a dish, sets it upon the altar.