While keeping the first watch during the night, I was enabled by the splendid moonlight to address a few lines in pencil to my friends at home. [Sidenote: Thursday, August 22nd.] The Kél-owí having had some difficulty in finding their camels, we did not move at an early hour. To our great astonishment we crossed the rocky bed of the torrent, and entered an irregular defile where a little further on we passed another pond of rain-water. When at length we emerged from the rocks, we reached a very high level, whence we had a clear prospect over the country before us. Four considerable ranges of mountains were clearly distinguishable in the distance, forming an _ensemble_ of which the accompanying sketch will give an idea. We then entered valleys clothed with a fine fresh verdure sprinkled with flowers, and with a luxuriant vegetation such as we had not seen before. The senna-plant (_Cassia senna_) appeared in tolerable quantity. Mountains and peaks were seen all around in a great variety of forms; and at twenty minutes past nine we had a larger mountain-mass on one side, from which a dry watercourse, marked by a broad line of herbage, issued and crossed our route. [Illustration] Having here allowed our camels a little feeding, we entered upon gravelly soil with projecting blocks of granite, and then went on ascending through a succession of small plains and valleys till we reached Erazar-n-Gébi, among the splendid vegetation of which we first observed the abísga, or _Capparis sodata_, called siwák or lirák by the Arabs, an important bush, the currant-like fruit of which is not only eaten fresh but also dried, and laid up in store, while the root affords that excellent remedy for the teeth which the Mohammedans, in imitation of their prophet, use to a great extent. The root moreover, at least on the shores of the Tsád, by the process of burning, affords a substitute for salt. It is the most characteristic bush or tree of the whole region of transition between the desert and the fertile regions of Central Africa, between the twentieth and the fifteenth degree of northern latitude; and in the course of my travels I saw it nowhere of such size as on the northern bank of the Isa or Niger, between Timbúktu and Gágho, the whole ground which this once splendid and rich capital of the Songhay Empire occupied being at present covered and marked out by this celebrated bush. As for the camels, they like very well to feed for a short time upon its fresh leaves, if they have some other herb to mix with it; but eaten alone it soon becomes too bitter for them. In this valley the little berries were not yet ripe; but further on they were ripening, and afforded a slight but refreshing addition to our food.