SECTION LXVII. Therefore the mosaic of the first dome, which is over the head of the spectator as soon as he has entered by the great door (that door being the type of baptism), represents the effusion of the Holy Spirit, as the first consequence and seal of the entrance into the Church of God. In the centre of the cupola is the Dove, enthroned in the Greek manner, as the Lamb is enthroned, when the Divinity of the Second and Third Persons is to be insisted upon together with their peculiar offices. From the central symbol of the Holy Spirit twelve streams of fire descend upon the heads of the twelve apostles, who are represented standing around the dome; and below them, between the windows which are pierced in its walls, are represented, by groups of two figures for each separate people, the various nations who heard the apostles speak, at Pentecost, every man in his own tongue. Finally, on the vaults, at the four angles which support the cupola, are pictured four angels, each bearing a tablet upon the end of a rod in his hand: on each of the tablets of the three first angels is inscribed the word "Holy;" on that of the fourth is written "Lord;" and the beginning of the hymn being thus put into the mouths of the four angels, the words of it are continued around the border of the dome, uniting praise to God for the gift of the Spirit, with welcome to the redeemed soul received into His Church: "HOLY, HOLY, HOLY, LORD GOD OF SABAOTH: HEAVEN AND EARTH ARE FULL OF THY GLORY. HOSANNA IN THE HIGHEST: BLESSED IS HE THAT COMETH IN THE NAME OF THE LORD." And observe in this writing that the convert is required to regard the outpouring of the Holy Spirit especially as a work of _sanctification_. It is the _holiness_ of God manifested in the giving of His Spirit to sanctify those who had become His children, which the four angels celebrate in their ceaseless praise; and it is on account of this holiness that the heaven and earth are said to be full of His glory.