On the keystone is a Greek cross within a circle. The outside of the arch is reached by passing through the Porta S. Sebastiano and turning to the left. It is formed of two round brick towers and a travertine stone arch, with grooves for a portcullis; on the outside keystone are the early Christian emblems of the labarum. The Roman Catholic tradition is that S. John the Evangelist was thrown into a caldron of boiling oil inside this gate, where the circular church now stands.
Opposite is the Church of S. John, Port Latin.
The little round church is called
S. GIOVANNI IN OLEO.
Mr. G. G. Scott lately discovered, at the Chapter House, Westminster, some frescoes representing the Visions of S. John, fourteenth century, which are described in the following inscriptions, translated by Canon Wordsworth:—
"To the most pious Cæsar, always Augustus, Domitian, the Proconsul of the Ephesians sends greeting:—We notify to your majesty that a certain man named John, of the nation of the Hebrews, coming into Asia, and preaching Jesus crucified, has affirmed him to be the true God and the Son of God; and he is abolishing the worship of our invincible deities, and is hastening to destroy the temples erected by your ancestors. This man, being contrariant—as a magician and a sacrilegious person—to your imperial edict, is converting almost all the people of the Ephesian city, by his magical arts and by his preaching, to the worship of a man who has been crucified and is dead. But we, having a zeal for the worship of the immortal gods, endeavoured to prevail upon him by fair words and blandishments, and also by threats, according to your imperial edict, to deny his Christ, and to make offerings to the immortal gods. And since we have not been able to induce him by any methods to do this, we address this letter to your majesty, in order that you may signify to us what it is your royal pleasure to be done with him."
"As soon as Domitian had read this letter, being enraged, he sent a rescript to the proconsul, that he should put the holy John in chains and bring him with him from Ephesus to Rome, and there assume to himself the judgment according to the imperial command."
"Then the proconsul, according to the imperial command, bound the blessed John the Apostle with chains, and brought him with him to Rome, and announced his arrival to Domitian, who, being indignant, gave command to the proconsul that the holy John should be placed in a boiling caldron, in presence of the senate, in front of the gate which is called the Latin Gate, when he had been scourged, which was done. But, by the grace of God protecting him, he came forth uninjured and exempt from corruption of the flesh. And the proconsul, being astonished that he had come forth from the caldron anointed but not scorched, was desirous of restoring him to liberty, and would have done so if he had not feared to contravene the royal command. And when tidings of these things had been brought to Domitian, he ordered the holy Apostle John to be banished to the island called Patmos, in which he saw and wrote the Apocalypse, which bears his name, and is read by us."
THE TOMB OF LUTATIUS CATULUS
is a lofty concrete tomb of the time of the republic, on the left, near the Church of S. John. This may be the general who ended the First Punic War, 242 B.C., or his descendant consul, 102 B.C., proscribed by Marius, and who suffocated himself with charcoal fumes.