On the 25th, at four in the morning, there being sufficient light, we slowly advanced amidst large blocks of quartz, among which I saw many thorny plants and stunted mimosas, the bare branches of which the famished camels cropped and ate with avidity. Whether these animals were sensible that they were approaching their own country and the moment when their wants would be satisfied, I know not, but they appeared more sprightly and vigorous than usual. About ten o’clock the same morning, we halted at the wells of Mayara, situated in a defile surrounded by granite and some mimosas. The water of these wells, which are only four or five feet deep, is salt; its taste is detestable: we had still one leather bottle full of good water, but the Moors would not allow me my share of it; they kept it all to themselves, and told me to go and drink with the camels. Three Moorish slaves, who were of our party, were more fortunate than I was; a small portion of the good water was given to them. At a hundred and fifty feet from the salt wells, there is another, the water of which is fit to drink, but it was nearly dry; several Moors passed part of the day in emptying it, and towards sunset I could quench my thirst at my ease. On the 26th, I was awakened at one in the morning: we proceeded N. N. E. between two hills sixty or seventy fathoms in height, composed of great blocks of grey quartz and some granites of the same colour: many mimosas and _hedysarum alhagi_ grow in this defile, the soil of which consists of grey sand. So long was it since I had seen any thing similar in point of vegetation, that I thought myself in the most beautiful country in the world. About eight in the morning, we entered a plain of black sand, in which we perceived here and there spots resembling little islands covered with herbage and mimosas. In proportion as we approached the limits of the desert, nature appeared less desolate. At eleven, we halted upon loose sand: we experienced the whole day a stifling heat, which created a dreadful thirst; as night drew on, some rice was boiled as usual for supper. About ten o’clock on the same day, we started towards the N. N. E., over a soil broken by deep ravines, on the edge of which some vegetation appeared. Our progress was slow, for the camels were allowed to graze as they went on; we proceeded but two miles an hour. At nine in the morning of the 27th, we stopped by the wells of Sibicia, situated between blocks of pale rose-coloured granite, and surrounded by a pleasant grove of date-trees, the verdure of which presented an agreeable contrast with the rest of the soil. The water of these wells, which are only seven or eight feet deep, is clear and delicious to drink.