In the Book of Common Prayer, in the Kalendar, on December the sixteenth, the words
O Sapientia
occur, which words some have fondly imagined to be the names of a Virgin and Martyr, whom they tried, “with much ingenuity and more ignorance,” to prove one of the companions of S. Ursula; (1) and others have confounded the
O Sapientia
with the mediaeval devotion of the XV. O's, (2) which in no shape or form was, at any time, part of a liturgical service, but merely fifteen private prayers each beginning with the letter 0, as may be seen in Mr. Maskell's Monumenta Ritualia. (3) These XV. O's, however, are of some interest, as they were printed by Caxton in English, and are to be found in most of our Prymers. (3)