TRAVELS IN THE SAHARA. 
mountains, which soon disappear as the winds blow. 
Shifting for a succession of ages, it is soon deposited 
in mounds, at regular intervals, which arrangement 
produces a continual succession of sand-showers, ex- 
cept when the air is entirely stagnant. When the 
sand-shower reaches the tents of the Arabs, they 
load their camels, turn their backs to the gale, and 
haste away ; which precaution alone can preserve 
them from being buried alive. This flying sand is 
the great obstacle to cultivation, for the soil of the 
desert is not every where unproductive. 
M. de Brisson, after having made several voy- 
ages to Africa, was wrecked a little to the north of 
Cape Blanco, and fell into the hands of the Labdes- 
seba Arabs. After escaping the shoals, his com- 
panions and he ascended the rocks on the shore, 
from the summits of which they saw the country 
expand in an immense plain, covered with white 
sand, over which were thinly scattered a few creep- 
ing plants resembling branches of coral. The seed 
of these plants was similar in form to that of mus- 
tard, but extremely small. The Arabs, who col- 
lect it to form an edible paste, term it avezoud. 
The distant hills, covered with wild fern, presented 
the appearance of an extensive forest. Proceeding 
towards some camels which they observed, they 
were discovered by some children tending the goats, 
and the alarm was soon spread to the tents of the 
