E SACRIFICE OF THE MASS

THE CONSECRATION OF THE ALTAR. 13
ing to the Sacrifice, are consecrated." (5. Th. vi. Dist.
q. i. a. 2.)
Blessings are divided into two classes : {benedictiones
invocativa) blessings that invoke God s favour and pro
tection merely, and blessings that set things aside
to the service of God alone (benedictiones constitutive).
The first class belongs to those things which after being
blessed are still retained for man s use and benefit, v.g.,
food blessed in the grace before meals. The second
refers to the sacred vestments and such-like things,
and in a much higher degree to the altar consecrated
by chrism and the holy oils.
The altar may be of wood or stone. The latter being
more durable is preferred. The altar on which our
Lord is said to have instituted the Blessed Sacrament
preserved in St. John Lateran at Rome, and the altar at
which St. Peter is thought to have said Mass still
existing in the same church, are of wood.
The horizontal slab of wood or stone forming the
top of the altar is called the Table, on which the Sacred
Body rests given to man as Food ; while the whole
altar, partly from its shape and partly from its connec
tion with the Sacrifice, and because it holds the relics,
is described as the tomb.
We speak of a fixed and of a portable altar, or altar-
stone. A fixed altar is one where the table is united to
the base by the sacred unction in such a way that if
separated it thereby loses its consecration.
The altar-stone or portable altar can be separated
from its base without losing its consecration.
The portable altar, a square piece of stone let into
the altar, is to all intents the altar. It should be
large
Host.
enough to hold on its surface the Chalice and