604 INLAND SAND PLAINS. 
so much from this cause, in proportion to their extent, as the 
peninsula of Jutland. So long as the woods, with which nature 
had planted the Danish dunes, were spared, they seem to have 
been stationary, and we have no historical evidence, of an 
earlier date than the sixteenth century, that they had become in 
any way injurious. From that period there are frequent noti- 
ces of the invasions of cultivated grounds by the sands; and 
excavations are constantly bringing to light proof of human 
habitation and of agricultural industry, in former ages, on soils 
now buried beneath deep drifts from the dunes and beaches of 
the seacoast.* 
Extensive tracts of valuable plain land in the Netherlands 
and in France have been covered in the same way with a layer 
of sand deep enough to render them infertile, and they can be 
restored to cultivation only by processes analogous to those 
employed for fixing and improving the dunes.t Diluvial sand 
plains, also, have been reclaimed by these methods in the 
Duchy of Austria, between Vienna and the Semmering ridge, 
in Jutland, and in the great champaign country of Northern 
Germany, especially the Mark Brandenburg, where artificial 
forests can be propagated with great ease, and where, conse- 
quently, this branch of industry has been pursued on a great 
scale, and with highly beneficial results, both as respects the 
supply of forest products and the preparation of the soil for 
agricultural use. 
As has been already observed, inland sands are generally 
looser, dryer, and more inclined to drift, than those of the 
seacoast, where the moist and saline atmosphere of the ocean 
keeps them always more or less humid and cohesive. The 
sands of the valley of the Lower Euphrates—themselves 
probably of submarine origin, and not derived from dunes— 
* For details, consult ANDRESEN, Om Klitformationen, pp. 223, 236. 
+ When the deposit is not very deep, and the adjacent land lying to the lee- 
ward of the prevailing winds is covered with water, or otherwise worthless, 
the surface is sometimes freed from the drifts by repeated harrowings, which 
loosen the sand, so that the wind takes it up and transports it to grounds 
where accu~ tions of it are less injurious. 
