'The natives, when they see the smoke, come down to the shore, and, laying out to view so much gold as they think the worth of the wares, withdraw themselves afar. The Carthaginians upon this come ashore and look. If they deem the gold sufficient they take it and wend their way; but if it does not seem to them sufficient, they go aboard once more and wait patiently. Then the others draw near and add to their gold till the Carthaginians are content. Neither party deals unfairly by the other; for they themselves never touch the gold till it comes up to the worth of their goods, nor do the natives ever carry off the goods till the gold is taken away.' Plato ('Critias' [Footnote: The celebrated Dialogue which treats of Altantis and describes cocoas as the 'fruits having a hard rind, affording drinks and meats and ointments.']) may refer to this dumb trade when he tells us, 'Never was prince more wealthy than Atlas [eldest son of Poseidon by Cleito]. His land was fertile, healthy, beautiful, marvellous; it was terminated by a range of gold-yielding mountains.' Lyon, speaking of the western Sudan, uses almost the very words of Herodotus. 'An invisible nation, according to our informant, inhabit near this place, and are said to trade by night. Those who come to traffic for their gold lay their merchandise in heaps and retire. In the morning they find a certain quantity of gold-dust placed against every heap, which if they think sufficient they leave the goods; if not, they let both remain till more of the precious ore is added' (p. 149). [Footnote: Shaw gives a similar account (_Travels_, p. 302).] The classical trade in gold and slaves was diligently prosecuted by the Arabs or Saracens after Mohammed's day. Their caravans traversed the great wilderness which lies behind the fertile Mediterranean shore, and founded negroid empires in the western Sudan, or Blackland. Ghana, whence, perhaps, the Portuguese Guine and our Guinea of 'the dreadful mortal name,' became the great gold-mart of the day. Famous in history is its throne, a worked nugget of solid gold, weighing 30 lbs. It has been rivalled in modern times by the 'stool' of Bontuko (Gyaman), and by the 'Hundredweight of gold' produced by New South Wales. Most of the wealth came from a district to the south-west, Wangara, Ungura, or Unguru, bordering on the Niger, and supposed to correspond with modern Mandenga-land. In the lowlands, after the annual floods, the natives dug and washed the diluvial deposits for the precious metal exactly as is now done upon the Gold Coast; and they burrowed into the highlands which surround in crescent-form the head-waters of the great River Joliba. Presently Tinbukhtu succeeded, according to Leo Africanus (1500), Ghana as the converging point of the trade, and made the name for wealth which endures even to the present day. Its princes and nobles lavishly employed the precious ore in ornaments, some weighing 1,300 ounces.