all, descended from Abas, the great-uncle of the Prophet. There were many others who at different times usurped the name of Caliph, but these seventy-two are all who are recognized as universal Caliphs. Mohammed XII., the last of these died in obscurity in Egypt in 1538. The power of the Caliphs gradually decayed, until for hundreds of years it was little more than nominal, and exclusively religious. The claim of the Ottoman Sultans to the Caliphate dates back to the time of Sultan Selim I. This Sultan conquered Egypt and over-threw the dynasty of the Mamelukes. He found at Cairo the Caliph Mohammed XII., and brought him as a prisoner to Constantinople. He was kept at the fortress of the Seven Towers for several years, and then sent back to Egypt with a small pension. While Selim was in Cairo, the Shereeff of Mecca presented to him the keys of the holy cities, and accepted him as their protector. In 1517 Mohammed XII. also made over to him all his right and title to the Caliphate. This involuntary cession, and the voluntary homage of the Shereeff of Mecca are the only titles possessed by the Ottoman Sultans to the Caliphate, which, according to the word of the Prophet himself, must always remain in his own family. If the Ommiades and the Abassides were imperfect Caliphs, it is plain that the Ottoman Sultans must be doubly imperfect. It was easy, however, for an all-powerful Sultan to obtain an opinion from the Ulema that his claim was well-founded; and it has been very generally recognized by orthodox Mohammedans, in spite of its essential weakness. When the time comes, however, that the Ottoman Sultans are no longer powerful, it will be still more easy to obtain an opinion that the Shereeff of Mecca, who is of the family of the Prophet, is the true Caliph. The Ottoman Sultans have also assumed the other and more generally used title of _Imam-ul-Mussilmin_, which may be roughly translated Grand Pontiff of all the Moslems, although, strictly speaking, the functions of an Imam are not priestly. This title is based upon an article of the Mohammedan faith which says--"The Mussulmans ought to be governed by an Imam, who has the right and authority to secure obedience to the law, to defend the frontiers, to raise armies, to collect tithes, to put down rebels, to celebrate public prayers on Fridays, and at Beiram," &c. This article of faith is based upon the words of the Prophet--"He who dies without recognizing the authority of the Imam of his time, is judged to have died in ignorance and infidelity." The law goes on to say--"All Moslems ought to be governed by one Imam. His authority is absolute, and embraces everything. All are bound to submit to him. No country can render submission to any other."