[Footnote B: The foregoing extract is taken from a book by the Rev. J.
Spencer Northcote, called _The Roman Catacombs, or some Account of the
Burial-Places of the Early Christians in Rome_: London, 1857. It is the
best accessible manual in English,--the only one with any claims to
accuracy, and which contains the results of recent investigations. Mr.
Northcote is one of the learned band of converts from Oxford to Rome. A
Protestant may question some of the conclusions in his book, but not its
general fairness. Our own first introduction to the catacombs, in the
winter of 1856, was under Mr. Northcote's guidance, and much of our
knowledge of them was gained through him. Mr. Northcote estimates the
total length of the catacombs at nine hundred miles; we cannot but think
this too high.]

This question of the number of the dead in the catacombs opens the way
to many other curious questions. The length of time that the catacombs
were used as burial-places; the probability of others, beside
Christians, being buried in them; the number of Christians at Rome
during the first two centuries, in comparison with the total number
of the inhabitants of the city; and how far the public profession
of Christianity was attended with peril in ordinary times at Rome,
previously to the conversion of Constantine, so as to require secret and
hasty burial of the dead;--these are points demanding solution, but of
which we will take up only those relating immediately to the catacombs.

There can, of course, be no certainty with regard to the period when the
first Christian catacomb was begun at Rome,--but it was probably
within a few years after the first preaching of the Gospel there. The
Christians would naturally desire to separate themselves in burial from
the heathen, and to avoid everything having the semblance of pagan
rites. And what mode of sepulture so natural for them to adopt, in