THE LANDES OF GASCONY. 
511 
pig on a former page, or as the sand hills of Poland, both of 
which seem better entitled to the appellation of sand waves than 
those of the Sahara or of the Arabian desert. The sands of 
the valley of the Lower Euphrates—themselves probably of 
submarine origin, and not derived from dunes—are advancing 
to the northwest with a rapidity which seems fabulous when 
compared with the slow movement of the sand hills of Gascony 
and the Low German coasts. Loftus, speaking of Niliyya, an 
old Arab town a few miles east of the ruins of Babylon, says 
that, “ in 1848, the sand began to accumulate around it, and in 
six years, the desert, within a radius of six miles, was covered 
with little, undulating domes, while the ruins of the city were 
so buried that it is now impossible to trace their original form 
or extent.” * Loftus considers this sand flood as the “ van¬ 
guard of those vast drifts which, advancing from the southeast, 
threaten eventually to overwhelm Babylon and Baghdad.” 
An observation of Layard, cited by Loftus, appears to me 
to furnish a possible explanation of this irruption. He “ passed 
two or three places where the sand, issuing from the earth 
like water, is called 6 Aioun-er-rummal,’ sand springs.” These 
“ springs ” are very probably merely the drifting of sand from 
the ancient subsoil, where the protecting crust of aquatic de¬ 
posit and vegetable earth has been broken through, as in the 
case of the drift which arose from the upturning of an oak 
mentioned on a former page. When the valley of the Eu¬ 
phrates was regularly irrigated and cultivated, the underlying 
sands were bound by moisture, alluvial slime, and vegetation ; 
but now, that all improvement is neglected, and the surface, no 
longer watered, has become parched, powdery, and naked, a 
mere accidental fissure in the superficial stratum may soon be 
enlarged to a wide opening, that will let loose sand enough to 
overwhelm a province. 
The Landes of Gascony . 
The most remarkable sand plain of France lies at the south¬ 
western extremity of the empire, and is generally known as 
* Travels and Researches in Chaldcea , chap. ix. 
