Note 10 — BOOK II.

[Pg 31][10] This island in the northern Ægean Sea has produced this "earth" from before Theophrastus' time (372-287 B.C.) down to the present day. According to Dana (System of Mineralogy 689), it is cimolite, a hydrous silicate of aluminium. The Ancients distinguished two kinds,—one sort used as a pigment, and the other for medicinal purposes. This latter was dug with great ceremony at a certain time of the year, moulded into cubes, and stamped with a goat,—the symbol of Diana. It thus became known as terra sigillata, and was an article of apothecary commerce down to the last century. It is described by Galen (XII., 12), Dioscorides (V., 63), and Pliny (XXXV., 14), as a remedy for ulcers and snake bites.