jan, the most
deserted and arid of all, reaches an altitude of nearly 4200 ft. Towards
the west the lesser causses of Rouergue and Quercy attain respectively
2950 ft. and 1470 ft. Once an uninterrupted table-land, the causses are
now isolated from one another by deep rifts through which run the Tarn,
the Dourbie, the Jonte and other rivers. The summits are destitute of
running water, since the rain as it falls either sinks through the
permeable surface soil or runs into the fissures and chasms, some of
great depth, which are peculiar to the region. The inhabitants
(_Caussenards_) of the higher causses cultivate hollows in the ground
which are protected from the violent winds, and the scanty herbage
permits of the raising of sheep, from the milk of which Roquefort
cheeses are made. In the west, where the rigours of the weather are less
severe, agriculture is more easily carried on.

CAUSSIN DE PERCEVAL, ARMAND-PIERRE (1795-1871), French orientalist, was
born in Paris on the 13th of January 1795. His father, Jean Jacques
Antoine Caussin de Perceval (1759-1835), was professor of Arabic in the
College de France. In 1814 he went to Constantinople as a student
interpreter, and afterwards travelled in Asiatic Turkey, spending a year
with the Maronites in the Lebanon, and finally becoming dragoman at
Aleppo. Returning to Paris, he became professor of vulgar Arabic in the
school of living Oriental languages in 1821, and also professor of
Arabic in the College de France in 1833. In 1849 he was elected to the
Academy of Inscriptions. He died at Paris during the siege on the 15th
of January 1871.

Caussin de Perceval published (1828) a useful _Grammaire arabe
vulgaire_, which passed through several editions (4th ed., 1858), and
edited and enlarged Elie Bocthor's[1] _Dictionnaire francais-arabe_ (2
vols., 1828; 3rd ed., 1864); but his great reputation rests almost
entirely on one book, the _Essai sur l'histoire des Arabes avant
l'Islamisme, pendant l'epoque de Mahomet_ (3 vols., 1847-1849), in which
the native traditions as to the early history of the Arabs, down to the
death of Mahommed and the complete subjection of all the tribes to
Islam, are brought together with wonderful industry and set forth with
much learning and lucidity. One of the principal MS. sources used is the
great _Kitab al-Aghani_ (Book of Songs) of Abu Faraj, which has since
been published (20 vols., Boulak, 1868) in Egypt; but no publication of
texts ca