ed column of white marble, which marks the spot where St.
Dominic, the founder of the order of the Dominicans, used to kneel
down and pray. It has received the name of Pietra di Paragone, or the
Touchstone. Another may be seen at the entrance of the church of Santa
Pudenziana, on the Esquiline, supposed to have been built on the site
of the house of the Roman senator Pudens, whose daughter, Pudentiana,
St. Peter is said to have converted to Christianity. A third exists
among the extensive collection of relics belonging to the ten thousand
three hundred martyrs whose remains, according to tradition, were
deposited in the church of S. Prassede, at the beginning of the ninth
century, by Paschal I. Two stones may be observed upon the gable wall
immediately above the basins of holy water in the interior of the
church of S. Nicolo in Carcere, near the Ghetto. Two others are
inserted in the wall of the Baptistery of St. John Lateran, between
the vestibule and the octagonal area containing the so-called gigantic
font in which Constantine was baptized. A very interesting stone hangs
suspended from the gilded iron grating which protects the crypt or
confessional of St. Laurence, immediately underneath the high altar of
the great Basilica of San Lorenzo beyond the Gate. A stone still more
remarkable, guarded by a strong iron grating, projects half its bulk
from the wall on the right-hand side of the arch which divides the
transept from the middle nave in the venerable church of Santa Maria
in Trastevere. Two other stones may be seen in the quaint old church
of SS. Cosma e Damiano at the south-eastern angle of the Roman Forum,
composed of portions of three pagan temples. They are inserted in the
plain whitewashed walls on both sides of the circular arch through
which you pass from the round vestibule into the interior of the
church. I have noticed similar stones in no less than twenty places
besides those I have mentioned; and I am assured that they may be seen
in many more churches.

It is very difficult to obtain any accurate or satisfactory
information regarding these curious stones. They go by the name of
_Lapides Martyrum_, or Martyr-stones. During the persecutions of the
early Christians in Rome they are said to have been hung round the
necks of those who were condemned to be drowned in the Tiber. In the
reign of the emperor Diocletian many martyrs perished in this way, and
the stones by which they were sunk beneath the fatal