The scales of iron,[1696] which are procured from a fine point or a sharp edge, are also made use of, being very similar in effect to rust, but more active; for which reason they are employed for defluxions of the eyes. They arrest bleeding, also, more particularly from wounds inflicted with iron; and they act as a check upon female discharges. They are applied, too, for diseases of the spleen, and they arrest hæmorrhoidal swellings and serpiginous ulcers. They are useful also for affections of the eyelids, gradually applied in the form of a fine powder. But their chief recommendation is, their great utility in the form of a hygremplastrum[1697] or wet plaster, for cleansing wounds and fistulous sores, consuming all kinds of callosities, and making new flesh on bones that are denuded. The following are the ingredients: of pitch, six oboli, of Cimolian chalk,[1698] six drachmæ, two drachmæ of pounded copper, the same quantity of scales of iron, six drachmæ of wax, and one sextarius of oil. To these is added some cerate, when it is wanted to cleanse or fill up wounds. CHAP. 47. (16.)—THE ORES OF LEAD. The nature of lead next comes to be considered. There are two kinds of it, the black and the white.[1699] The white is the most valuable: it was called by the Greeks “cassiteros,”[1700] and there is a fabulous story told of their going in quest of it to the islands of the Atlantic, and of its being brought in barks made of osiers, covered with hides.[1701] It is now known that it is a production of Lusitania and Gallæcia.[1702] It is a sand found on the surface of the earth, and of a black colour, and is only to be detected by its weight. It is mingled with small pebbles, particularly in the dried beds of rivers. The miners wash this sand, and calcine the deposit in the furnace. It is also found in the gold mines that are known as “alutiæ,”[1703] the stream of water which is passed through them detaching certain black pebbles, mottled with small white spots and of the same weight[1704] as gold. Hence it is that they remain with the gold in the baskets in which it is collected; and being separated in the furnace, are then melted, and become converted into white lead.[1705]