Eck gradually recovered courage. Repairing to Erfurt, whose theologians had on more than one occasion betrayed their jealousy of Luther, he insisted on having his bull published in this town, but the students seized the copies, tore them to pieces, and threw them into the river, saying, "since it is a bull, let it swim."[275] "Now," said Luther, on being informed of this, "the pope's paper is a true bull." Eck durst not make his appearance at Wittemberg; but he sent the bull to the rector with a threat, that if it was not conformed to, he would destroy the university. At the same time he wrote Duke John, Frederick's brother, and co-regent, "Do not take what I do in bad part, I am acting in behalf of the faith, and it costs me many cares, great labour, and much money."[276] [275] A studiosis discerpta et in aquam projecta, dicentibus: Bulla est, in aquam natet! (L. Ep. i, p. 520.) [276] Mit viel Mühe, Arbeit, und Kosten. (L. Op. (L.) xvii, p. 317.) [Sidenote: ULRICK ZUINGLIUS.] The bishop of Brandenburg, supposing him inclined, was not entitled to act at Wittemberg in his capacity of ordinary, the university being protected by its privileges. Luther and Carlstadt, who were condemned by the bull, were asked to take part in the meetings which were held to deliberate on its contents. The rector declared that, as he had not received a letter from the pope along with the bull, he declined to publish it. The university had already acquired greater authority in the surrounding countries than the sovereign pontiff himself. Its declaration served as a model to the government of the Elector; and thus the spirit which was in Luther triumphed over the bull of Rome. [Sidenote: LUTHER'S SELF-EXAMINATION.]