The most ancient type of daric was thick and irregular in shape, and rudely stamped, but of remarkable fineness, the amount of alloy being never more than three per cent. The use of this coinage was nowhere obligatory, and it only became general in the countries bordering on the Mediterranean, where it met the requirements of international traffic and political relations, and in the payment of the army and the navy. In the interior, the medium of exchange used in wholesale and retail commercial transactions continued to be metals estimated by weight, and the kings of Persia themselves preferred to store their revenues in the shape of bullion; as the metal was received at the royal treasury it was melted and poured into clay moulds, and was minted into money only gradually, according to the whim or necessity of the moment.* * Arrian relates that Alexander found 50,000 talents' weight of silver in the treasury at Susa; other hoards quite as rich were contained in the palaces of Persepolis and Pasargadae. Taxes in kind were levied even more largely than in money, but the exact form they assumed in the different regions of the empire has not yet been ascertained. The whole empire was divided into districts, which were charged with the victualling of the army and the court, and Babylon alone bore a third of the charges under this head. We learn elsewhere that Egypt was bound to furnish corn for the 120,000 men of the army of occupation, and that the fisheries of the Fayum yielded the king a yearly revenue of 240 talents. The Medes furnished similarly 100,000 sheep, 4000 mules, and 3000 horses; the Armenians, 30,000 foals; the Cilicians, 365 white horses, one for each day in the year; the Babylonians, 500 youthful eunuchs; and any city or town which produced or manufactured any valuable commodity was bound to furnish a regular supply to the sovereign. Thus, Chalybon provided wine; Libya and the Oases, salt; India, dogs, with whose support four large villages in Babylonia were charged; the AEolian Assos, cheese; and other places, in like manner, wool, wines, dyes, medicines, and chemicals. These imperial taxes, though they seem to us somewhat heavy, were not excessive, but taken by themselves they give us no idea of the burdens which each province had to resign itself to bear. The state provided no income for the satraps; their maintenance and that of their suite were charged on the province, and they made ample exactions on the natives. The province of Babylon was required to furnish its satrap daily with an _ardeb_ of silver; Egypt, India, Media, and Syria each provided a no less generous allowance for its governor, and the poorest provinces were not less heavily burdened. The satraps required almost as much to satisfy their requirements as did the king; but for the most part they fairly earned their income, and saved more to their subjects than they extorted from them.