Two only of these products seem to deserve a longer description.  The Cyrenaic silphium, of which we hear so much, as constituting the main wealth of that province, was valued chiefly for its medicinal qualities.  A decoction from its leaves was used to hasten the worst kind of labors; its root and a juice which flowed from it were employed in a variety of maladies.  The plant, which is elaborately described by Theophrastus, appears to have been successfully identified by modern travellers in the Cyrenaica, who see it in the drias or derias of the Arabs, an umbelliferous plant, which grows to a height of about three feet, has a deleterious effect on the camels that browse on it, and bears a striking resemblance to the representations of the ancient silphium upon coins and medals.  This plant grows only in the tract between Merj and Derna—­the very heart of the old silphium country, while that it has medicinal properties is certain from its effects upon animals; there can thus be little doubt that it is the silphium of the ancients, somewhat degenerated, owing to want of cultivation.

The Egyptian byblus or papyrus (Cyperus papyrus) was perhaps the most valuable of all the vegetables of the Empire.  The plant was a tall smooth reed of a triangular shape.  It grew to the height of ten or fifteen feet, and terminated in a tuft or plume of leaves and flowers.  Though indigenous in the country, it was the subject of careful cultivation, and was grown in irrigated ground, or in such lands as were naturally marshy.  The root of the plant was eaten, while from its stem was made the famous Egyptian paper.  The manufacture of the papyrus was as follows; The outer rind having been removed, there was exposed a laminated interior, consisting of a number of successive layers of inner cuticle, generally about twenty.  These were carefully separated from one another by the point of a needle, and thus were obtained a number of strips of the raw material, which were then arranged in rows, covered with a paste, and crossed at right angles by another set of strips placed over them, after which the whole was converted into paper by means of a strong pressure.  A papyrus roll was made by uniting together a greater or less number of such sheets.  The best paper was made from the inmost layers of cuticle.  The outer rind of the papyrus was converted into ropes; and this fabric was found to be peculiarly adapted for immersion in water.

The mineral treasures of the Empire were various and abundant.  It has been noticed already that Persia Proper, if we include in it Carmania, possessed mines of gold, silver, copper, iron, red lead, orpiment, and salt, yielding also bitumen, naphtha, sulphur, and most probably common lead.  We are further informed by ancient writers that Drangiana, or Sarangia, furnished the rare and valuable mineral tin, without which copper could not be hardened into bronze; that Armenia yielded emery, so necessary for the working