On the 24th we rested, and having proceeded the following morning, employed five days more in reaching Leghea. Water there is scarce, and far inferior in quality to that of Selimé, having a brackish taste. The camels throughout the caravan began now to be excessively weak and jaded, and the Chabir was at a loss for the true road: for though several persons in the caravan had traversed this desert ten or twelve times, they were not unfrequently unable to determine which was the right course. One of the party was sent forward to discover some known object that might be our guide, and after having been absent thirty-six hours he returned. While we remained here we felt much inconvenience from a suffocating wind that blew from the South, and raised the sand in clouds. On the 2d of July the caravan left Leghea; and on the eighth, after a severe and fatiguing march, reached the Bir-el-Malha or salt spring. The vicinity of this spring is remarkable for the production of _natron_, which substance appears under different circumstances, and is of different quality from that of Terané. It is very white and solid; and on immersion in water becomes hot, and discharges a great portion of its air. Small quantities of it are carried by the jelabs to Egypt, where it is sold at a high price, and is used principally in making snuff. The water found at this place is very unpalatable, being brackish. A troop of the natives of Zeghawa met us at this well. It is their practice to station a small party there, when caravans are expected, who remunerate themselves for the fatigue of a ten days journey by supplying provisions, and what else may be wanted by travellers, at an exorbitant rate. Many of our companions at this time had great need of their assistance, as their supply had been originally insufficient, and many camels had perished on the road. The vicinity of the Bir-el-Malha is occasionally infested by the Cubba-Beesh, a wandering tribe, who, mounted on the swiftest dromedaries, rapidly traverse the desert, and live by plundering the defenceless. As they are, however, unfurnished with fire-arms, so numerous a body as ours was not in much danger from their attack. We remained at the Bir-el-Malha till the 12th; on which day we left that place, and travelled with little interruption till the 20th, and then encamped at a spot called Medwa, where however is no supply of water. One of my camels having fallen, we were obliged to purchase water of the _Mahréa_ Arabs[34] whom we met, or to take up what had lodged in cavities on the earth, in consequence of the rains which were then beginning to fall.