tificia_ the cardinal titles number fifty-three; since the highest
possible number of cardinal priests is fifty, and this number is never
reached, it follows that there are always a certain number of vacant
titles. The first title is that of San Lorenzo in Lucina, and the
cardinal priest of the oldest standing takes the name of "first priest,"
_protopresbyter_.

Cardinal deacons.

The third order of cardinals is that of the cardinal deacons. For a long
time the Roman Church, faithful to the example of the primitive church
at Jerusalem (Acts vi.), had only seven deacons. Their special function
was the administration of her temporal property, and particularly works
of charity. Between them were divided at an early date the fourteen
districts (_regiones_) of Rome, grouped two by two so as to constitute
the seven ecclesiastical districts. Now the charitable works were
carried on in establishments called _diaconiae_, adjoining churches
which were specially appropriated to each _diaconia_. The connexion
between the names (_diaconus_) and (_diaconia_) and the presence of a
church in connexion with each diaconia gradually established for the
deacons a position analogous to that of priests. In the 8th century Pope
Adrian found sixteen diaconiae and founded two others (_Lib. Pont._ ed.
Duchesne, i. p. 509); in the 12th century the cardinal deacons, who then
numbered eighteen, were no longer distinguished by an ecclesiastical
district, as they had formerly been, but by the name of the church
connected with some diaconia (loc. cit. p. 364). By the time of Sixtus
V. the connexion between a cardinal deacon and his diaconia was merely
nominal. Sixtus reduced the number of cardinal deacons to fourteen; and
this is still the number to-day. Except that his church is called a
diaconia, and not a title, the cardinal deacon is in this respect
assimilated to the cardinal priest; but he does not mention his diaconia
in his official signature: e.g. "Joannes Henricus diaconus cardinalis
Newman." There are at present sixteen diaconiae, the chief being that of
Santa Maria in Via lata; the cardinal deacon of longest standing takes
the name of "first deacon," _protodiaconus_.

Cardinals can pass from one order, title or see to another, by a
process of "option." When a suburbicarian see falls vacant, the
cardinals resident at Rome have the right of "opting" for it in order
of rank,--that is to say, of claiming it in consistory and rece