The story of this adventure spread abroad, and made its way beyond
the usual gossip of the Forestieri, even into Italian circles, where,
enhanced by a still potent spirit of superstition, it grew far more
wonderful than as above recounted. Thence, it came back among the
Anglo-Saxons, and was communicated to the German artists, who so richly
supplied it with romantic ornaments and excrescences, after their
fashion, that it became a fantasy worthy of Tieck or Hoffmann. For
nobody has any conscience about adding to the improbabilities of a
marvellous tale.

The most reasonable version of the incident, that could anywise be
rendered acceptable to the auditors, was substantially the one suggested
by the guide of the catacomb, in his allusion to the legend of Memmius.
This man, or demon, or man-demon, was a spy during the persecutions
of the early Christians, probably under the Emperor Diocletian, and
penetrated into the catacomb of St. Calixtus, with the malignant purpose
of tracing out the hiding-places of the refugees. But, while he stole
craftily through those dark corridors, he chanced to come upon a little
chapel, where tapers were burning before an altar and a crucifix, and
a priest was in the performance of his sacred office. By divine
indulgence, there was a single moment's grace allowed to Memmius, during
which, had he been capable of Christian faith and love, he might have
knelt before the cross, and received the holy light into his soul, and
so have been blest forever. But he resisted the sacred impulse. As
soon, therefore, as that one moment had glided by, the light of the
consecrated tapers, which represent all truth, bewildered the wretched
man with everlasting error, and the blessed cross itself was stamped
as a seal upon his heart, so that it should never open to receive
conviction.