Bull. The word is derived from the Lat. bulla, 'a bubble of water,' and then 'a round ball of any kind.' In the middle ages it came to signify the capsule of the seal appended to letters from emperors or popes, next it was used for the seal itself, and lastly for the document to which the seal was appended. Its use is now commonly restricted to papal documents issued with certain indispensable formalities.
These formalities have varied greatly from age to age, and we must content ourselves with an account of the modern practice down to December 1878, and of the changes made at that date by the reigning pontiff Leo XIII. Down to that time, a bull had a seal, usually of lead, occasionally of gold, attached to it. On one side was the official name of the pope (e.g. Gregory XVI., Pius IX.), on the other the heads of Peter and Paul, separated by a cross and surmounted by the letters SPE (i.e. 'Sanctus Petrus') and SPA (i.e. 'Sanctus Paulus') respectively. The seal was fastened by red or yellow silk, or by uncoloured hemp, according to the nature of the contents. Bulls were written on strong parchment and in the Latin tongue. They began with the words 'N. episcopus servus servorum Dei dilecto filio (or dilectis filiis, &c.), salutem et apostolicam benedictionem.' Sometimes in cases where permanent decisions were given or privileges of great moment conferred, the words 'In perpetuum,' or 'In æternam rei memoriam,' were substituted for 'Salutem et apostolicam benedictionem.' Sometimes, also, when no special persons were addressed, 'In perpetuum,' &c., immediately follows the 'Servus servorum Dei.' Usually signatures are added below in testimony that the bull is authentic. Formerly it was common for the cardinals to sign; later on this was done by various members of the curia, specially by the protodatary, secretary of briefs, and vice-chancellor. The bull is dated according to the year of the incarnation, the year of the pontificate, and the day of the month after the old Roman reckoning. The character used from the reign of Adrian VI. to our own day is of that crabbed and indistinct kind known as 'littera S. Petri,' or in Italy as the 'carattere bollatico' or 'teutonico.' Finally, the bull is expedited from the apostolic chancery in the Vatican.
By a Motu proprio of December 9, 1878, Leo XIII. ordained that the leaden seal in use for more than a thousand years should be employed henceforth only in case of bulls concerning collations, erections, and dismemberments of greater benefits (reserved to the pope), and other solemn acts of the holy see. In other bulls, 'especially those relating to ordinary benefits and marriage dispensations, the old leaden seal is to be replaced by a red one stamped on the parchment itself, with the heads of St Peter and St Paul surrounded by the name of the reigning pope. The ordinary Latin current writing is henceforth to displace the Gothic character.
The divisions of bulls into different species—e.g. 'consistoriales,' issued after consultation in consistory; 'dimidie,' by a pope not yet crowned, &c.—possess little general interest. If we add to the words of Leo XIII., just quoted, bulls conveying doctrinal decisions, we have a correct idea of the objects for which bulls are published. It is a mistake to suppose that bulls are always, and of necessity, more important than briefs.
A Bullarium is a collection made without official authority of papal documents (not necessarily bulls in the strict sense) which have not found a place in the Corpus Juris. A bullarium may contain the acts of a particular pope, or may be limited to bulls relating to particular orders, churches, &c., or it may comprise bulls of all ages, and on all kinds of subjects, excluding only those already to be found in the Corpus Juris. The first bullarium appeared at Rome in 1586, edited by Cherubini. The most convenient is that published at Turin (24 vols. 1857–72).