You find thus in the very sands an anticipation of the vegetable leaf.
It is marked by grey clays and sands, lignitic fossiliferous clays, beds of lignite or brown coal, sometimes 8 ft.
In Roman times the Rhine at this part of its course seems to have been a full and flowing river, but by the 9th century it had lost itself in the sands of Katwijk, and it was not until the beginning of the 19th century that its way to the sea was re-opened.
Dressing auriferous sands,gravels,&c.; 2.
The landscape around them was bleak, almost as devoid of plant life as the white sands had been.