278 TRAVELS IN THE SAHARA. 
hard to the touch. Neither the wood, nor the en- 
closed dust, nor the calcined stones, had either 
taste or smell. At some distance, the mountains, 
which were extremely high, seemed to be piled „ 
above each other in immense ranges, from whence 
enormous blocks appeared to have fallen, and to have 
been shattered to pieces before reaching the ground. 
These detached masses, over which other rocks 
hung suspended, formed immense caverns, and co- 
vered the valleys. From another quarter, two 
fountains issued, one of which drew along in its 
course a black slimy matter of a sulphureous smell. 
The other, separated from the first by a small 
isthmus of sand, of the breadth of 12 or 15 paces, 
was clearer than crystal. In a valley, which ap- 
peared at first sight extremely circumscribed by 
the surrounding mountains, and the detached 
rocks which were heaped up in promiscuous con* 
fusion, Brisson discovered an astonishing variety of 
scenery. At the entrance of the valley, the ground 
was moist and furrowed, as if it had been formerly 
watered by winding rivulets. The borders of these 
furrows were covered with beds of pebbles, and 
crusted over with a nitrous kind of ice. The rocks 
which enclosed the furrows were covered with 
the same, and resembled cascades. Thick reddish 
roots and branches, covered with leaves like those 
of the laurel, crept across the different crevices. 
As he advanced, pyramids of great stones, white 
