Ancient Persia produced a certain number of gems. The pearls of the Gulf, which have still so great a reputation, had attracted the attention of adventurers before the time of Alexander, whose naval captains found a regular fishery established in one of the islands. The Orientals have always set a high value on this commodity; and it appears that in ancient times the Gulf pearls were more highly esteemed than any others. Of hard stones the only kinds that can be distinctly assigned to Persia Proper are the iritis, a species of rock-crystal; the atizoe, a white stone which had a pleasant odor; the mithrax, a gem of many hues, the nipparene, which resembled ivory; and the the lycardios or mule, which was in special favor among the natives of the country. From this account of the products of Persia Proper we have now to pass to those of the Empire in general--a wide subject, which it will be impossible to treat here with any completeness, owing to the limits to which the present work is necessarily confined. In order to bring the matter within reasonable compass, the reader may be referred in the first instance to the account which was given in a former volume of the products of the empire of Babylon; and the enquiry may then be confined to those regions which were subject to Persia, but not contained within the limits of the Fourth Monarchy. Among the animals belonging to these regions, the following are especially noticeable:--The tiger, the elephant, the hippopotamus, the crocodile, the monitor, the two-humped camel, the Angora goat, the elk, the monkey, and the spotted hysena, or _Felis chaus_. The tiger, which is entirely absent from Mesopotamia, and unknown upon the plateau of Iran, abounds in the low tract between the Elburz and the Caspian, in the flat region about the Sea of Aral, and in the Indus valley. The elephant was, perhaps, anciently an inhabitant of Upper Egypt, where the island of Elephantine remained an evidence of the fact. It was also in Persian times a denizen of the Indus valley, though perhaps only in a domesticated state. The hippopotamus, unknown in India, was confined to the single province of Egypt, where it was included among the animals which were the objects of popular worship. The crocodile--likewise a sacred animal to the Egyptians--frequented both the Nile and the Indus. Monitors, which are a sort of diminutive crocodiles, were of two kinds: one, the _Lacerta Nilotica_, was a water animal, and was probably found only in Egypt; the other, _Lacerta scincus_, frequented dry and sandy spots, and abounded in North Africa and Syria, as well as in the Nile valley. The two-humped camel belonged to Bactria, where he was probably indigenous, but was widely spread over the Empire, on account of his great strength and powers of endurance.