directly) and to a later type of _devotio_ used at the siege of
Carthage and preserved by Macrobius.[433] Thirdly, in spite of this
religious aspect of the formula, it ends with what can only be called a
magical spell. By the act of self-sacrifice, which is the potent element
in the spell, Decius exercises magical power over the legions of the
enemy, and devotes them with himself to death,--to the Manes and Mother
Earth.[434]

The story suggests to me that the rite had been at one time well known;
the pontifex maximus was ready with the instructions and formula. It was
a survival from an age of magic, but the priests have given it a
religious turn, and the language of the first part is quite as much that
of prayer as is the language of the collect to be said in time of war
which still disfigures the Anglican prayer-book.[435] What is still more
remarkable is that it has not only a religious but an ethical character.
The idea of service to the State is here seen at its highest point. The
sacrifice is a vicarious one.[436] Livy significantly adds that a
private soldier might be chosen by the commander to represent him, and
that if this man were not killed by the enemy an image seven feet long
must be buried in the earth and a piacular sacrifice offered.[437] Later
on it would seem that instead of sacrificing himself, the consul might
implore the gods to accept the hostile army or city as his substitutes:
"eos _vicarios_ pro me fide magistratuque meo pro populi Romani
exercitibus do devoveo, ut me exercitumque nostrum ... bene salvos
siritis esse."[438] The idea here, and indeed in the _devotio_ of
Decius, bears some analogy to that which lies at the root of the old
Roman practice, of making a criminal _sacer_ to the deity chiefly
concerned in his crime; when this was done, any man might kill him, and
he was practically a victim offered as _vicarius_ for the Roman people,
who had been contaminated by his deed.[439]

But I must now pass on the last kind of ritual to be explained in these
lectures, and far the most impressive of all, that of _lustratio_, or
the purification, as it is commonly called, of land, city, human beings,
or even inanimate objects, by means of a solemn procession accompanied
with sacrifice.

So important a part did these processional rites play in the public life
of the Roman people,--so characteristic are they too of the old Roman
habit of thought and action, that they have given a wonderful word