 In 1731 Pope Clement XII issued a very minute code of instructions for the proper carrying out of the "Quarant'Ore" devotion, which is known as the "Instructio Clementina".The Plenary Council of Baltimore approved the Forty Hours Devotion for all Catholic dioceses in the United States in 1866.Before the year 1550 this, or some analogous exposition, had been established by St. Philip Neri for the Confraternity of the Santissima Trinità dei Pellegrini in Rome; while St. Ignatius Loyola, also encouraged the practice of exposing the Blessed Sacrament during the carnival as an act of expiation for the sins committed at that season.