A correct and clear understanding as well as frequent consider ation of the profound and mystical Rite Of the Mass, will, in all probability, be the best means to enable the purest to refrain from a thoughtless, habitual mannerism, and lead hlm to celebrate the adorable mysteries Of the Altar with becoming attention, devotion, and reverence. The priest who studies this book will, moreover, find manifold reasoning and argument wherewith to direct the faith ful according to their capacity in the proper understanding Of the Divine Sacrifice and in their fervent recourse to the Eucharistic fountain Of grace. The authorities Of the Church have often im pressed upon pastors, that this is a chief duty Of directors Of souls, for the conscientious discharge Of which they shall have to render an account before God. Although this volume is principally in tended for the use of the clergy, it has been so arranged that the more highly cultured Of the laity may also peruse it with profit.