Hearing is, in its turn, affected. Then, any sound whatsoever, such as a footfall, the blow of a stone, the whisper of the wind, is changed into melodious sounds, keen cries of distress, the murmur of woods, the harmony of familiar songs. One day, says M. d'Escayrac, I heard the click-clack of a village mill. Endeavouring to collect my senses, and to obtain an explanation of the sound, I perceived that it arose from the clink of my sword-belt against the pommel of my saddle, to which I had buckled my sabre. Jomard, the savant, who experienced the effects of the ragle during his travels in Egypt, confirms in every respect the foregoing description. On his way from Rosetta to Alexandria, he kept along the border of the sea, and found his feet painfully staggering in the thick fine sand. Such a journey is necessarily one of extreme fatigue. After the first night, this fatigue grew overwhelming; the traveller lost all accurate perception of objects, or of the form of places. The surface of the lake Medeah appeared not so much a sheet of water as a monotonous plain. Constantly pressing forward, he maintained a hard fight against the overpowering sense of slumber. Half-asleep, half-awake, his brain was dazzled with the most fantastic phantoms, and the hallucination was so great that he plunged into the lake before him, without perceiving it, though the water was very deep. But the freshness caused by the evaporation of the water warned him of his error, and the vision suddenly passed away. Such being the phenomena of the Desert, one can understand the dreary picture which Dante paints in his "Inferno," of-- "The plain Which from its bed rejecteth every plant;" whose soil is-- "Of an arid and thick sand;" and where-- "With a gradual fall Are raining down dilated flakes of fire. As of the snow on Alp, without a wind."[66] CHAPTER V. VEGETABLE LIFE IN THE DESERT:--THE OASES. The _Flora_ of a region where nature provides no genial fertilizing rains, and whose soil is simply a shifting sand, moistened only in certain places by a brackish water, must necessarily be one of extreme poverty.