This book is one of the Westminster Library, a series of manuals for Catholic priests and students. This book is presented to the reader as a useful manual, and not as an exhaustive treatise. Contents: The Institution; Real Presence; Transubstantiation; Holy Eucharist as a Sacrament; Use of the Holy Eucharist as a Sacrament; Effects of the Sacrament of the Holy Eucharist; On Frequent Communion; Eucharistic Sacrifice; Mass as a Liturgy; Mass at the Present Day; Fruits and Effects of the Holy Sacrifice of the Mass; Cultus of the Blessed Sacrament.