To Lydia we owe the invention of coinage. The business of the world had previously been conducted either by barter or by bullion (gold bars of a certain weight). Every merchant had to carry a set of scales with him to see that he was not being cheated. Henceforth, as a guarantee of purity and weight, the state fixed its own stamp on pieces of metal, cut up into convenient sizes. This was a great help to commerce and was adopted everywhere. To another people, the Phoenicians, who were absorbed in the Persian Empire, we owe our alphabet, which, unlike the four hundred signs of the Babylonians, contains a very small number of letters, and makes written speech easy. The device came originally from Egypt, but the Phoenicians, who lived on the coast of Syria, adopted it and taught it to the Greeks. They arranged twenty-two consonants in a fixed order, and gave them names by which they could easily be learned. When the Greeks borrowed this list in the ninth century B.C., they added vowels to it, to make the spelling of words more simple. The Romans borrowed this improved alphabet from the Greeks who settled in Italy, and handed it on to us. (The word " alphabet " is derived from the Greek words alpha and beta, which were themselves of Phoenician origin, and were used for the " A " sound and the " B " sound respectively.) The Phoenicians, issuing from their seaports, Tyre and Sidon, won a monopoly of the carrying trade of the Mediterranean. At the centre of the north coast of Africa, they founded the great seaport of Carthage. They even passed through the straits of Gibraltar and founded a city at Gades (Cadiz) on the Atlantic coast of Spain. Cotton and spices from India, tin from Spain, and amber from the Baltic were distributed by them to all countries. After the fall of Nineveh, Babylon flourished for a short time under Nebuchadnezzar (605-561 B.C.), who carried o;i the Jews into captivity. But the political vitality of the Semitic peoples had ebbed. The last king occupied himself with antiquarian research and religious quarrels, and was easily swept aside when the priests treacherously opened the gates to Cyrus in 538 B.C. The victories of Cyrus mark the first triumph of Aryan over Semite in the struggle for Western Asia, but though Cyrus laid the foundations, it was Darius (521-485 B.C.) who successfully organised the empire. Avoiding the Assyrian policy of oppression and extortion, he allowed the subject provinces a good deal of internal freedom. The empire was treated as a business proposition and carefully nursed so as to bring in good returns.