This work is both a spiritual and practical preparation for celebrating the Latin Tridentine Mass in a holy manner. THE remote preparation for the worthy celebration of Mass consists in studying the excellence of this sacrifice, considering the necessity of a holy life for the worthy offering of it, bestowing special thought on the special virtues which this sublime function demands of the priest, and the powerful aids afforded him in this action for the attainment of an eminent degree of perfection. The proximate preparation consists in exercises of piety, whose object is to excite in the soul sentiments conformable to this angelical function. THE vestments which the Church wishes her ministers to use in the discharge of their functions at the altar are emblems well suited to express their meaning, and at the same time urgent exhortations to innocence of life, piety, fervor-and, in a word, to the virtue of justice, which comprises in itself all perfection, and is the true Iivery of our priesthood. "Sacerdotes tui induantuf justitiam." "Eluceat in eis totius forma justitire." There are, however, three virtues which appear to be more indispensable than the others to the priest who celebrates: viz., a lively faith, a deep religious feeling, an eminent purity.