332                                             BOOK VIII.
	Some people, in place of a green cloth, use a cloth of tightly woven horsehair, which has a rough knotty surface. Since these knots stand out
	and the cloth is rough, even the very small particles of gold adhere to it ; these cloths are likewise washed in a tub with water. " stream carries mud with it. This kind of earth is called urium, hence these ditches are " laid out to carry the water over beds of pebbles to avoid this urium. When they have " reached the head of the fall, at the top of the mountain, reservoirs are excavated a couple " of hundred feet long and wide, and about ten feet deep. In these reservoirs there are " generally five gates left, about three feet square, so that when the reservoir is full, the gates " are opened, and the torrent bursts forth with such violence that the rocks are hurled along. " When they have reached the plain there is yet more labour. Trenches called agogae are " dug for the flow of the water. The bottoms of these are spread at regular intervals with ulex " to catch the gold. This ulex is similar to rosemary, rough and prickly. The sides, too, " are closed in with planks and are suspended when crossing precipitous spots. The earth " is carried to the sea and thus the shattered mountain is washed away and scattered ; and " this deposition of the earth in the sea has extended the shore of Spain. . . . The gold " procured from arrugiae does not require to be melted, but is already pure gold. It is found " in lumps, in shafts as well, sometimes even exceeding ten librae in weight. These lumps " are called palagae and palacurnae, while the small grains are called baluce. The Ulex is " dried and burnt and the ashes are washed on a bed of grassy turf in order that the gold " may settle thereon."