It is a fundamental law in Aheer, that the Sultan of Aghadez shall belong to a particular family, which is said to derive its origin from Constantinople. Therefore when, in consequence of some discontent, Abd-el-Kader was deposed last year, the malcontents chose a relative, Hamed-el-Argau; but he also displeasing, a rival was set up in Makita, also of the same family. This caused great confusion, and the Walad Suleiman took the opportunity to make forays against Aheer. The prudent then resolved to restore the old Sultan, and succeeded, as I have already said, in their endeavours. When Dr. Barth arrived in Aghadez, the investiture was about to take place. The Sultan is chosen by the Kilgris and Iteesan tribes, who nourish a deadly hatred against their kindred, the Kailouees. On the present occasion, however, a marabout proclaimed peace and good-will between these ancient enemies. It was necessary, indeed, that some understanding should be come to, as after the election the ratification of En-Noor and Lousou is required. En-Noor, especially, is greatly respected by the people of Aghadez, as the grand supporter of authority in Asben. The new Sultan is usually brought from Sakkatou in state by the tribes Iteesan and Kilgris. A vast crowd of them, with their families and flocks, had marched up and occupied a camp near the town; but they departed on the same day that Dr. Barth arrived--even before he entered. Early in the morning, Dr. Barth paid his respects to the Sultan. He was a stout man, about fifty-five years of age--benevolent-looking, as far as could be judged in spite of his face-wrappers. He sat in a large room, supported by two massive columns, and received his visitors kindly. The presents pleased him, and were acknowledged by the counter-present of a fat ram, and by meals sent every day.