When the various ores were obtained, they were first of all crushed, then pounded to a paste; after which, by frequent washings, the non-metallic elements were to a large extent eliminated, and the metallic ones alone left. These, being collected, were placed in crucibles of white clay,[1038] which were then submitted to the action of a furnace heated to the melting point. This point could only be reached by the use of the bellows. When it was reached, the impurities which floated on the top of the molten metal were skimmed off, or the metal itself allowed, by the turning of a cock, to flow from an upper crucible into a lower one. For greater purity the melting and skimming process was sometimes repeated; and, in the case of gold, the skimmings were themselves broken up, pounded, and again submitted to the melting pot.[1039] The use of quicksilver, however, being unknown, the gold was never wholly freed from the alloy of silver always found in it, nor was the silver ever wholly freed from an alloy of lead.[1040] The Romans and Carthaginians worked their mines almost wholly by slave labour; and very painful pictures are drawn of the sufferings undergone by the unhappy victims of a barbarous and wasteful system.[1041] The gangs of slaves, we are told, remained in the mines night and day, never seeing the sun, but living and dying in the murky and foetid atmosphere of the deep excavations. It can scarcely be hoped that the Phoenicians were wiser or more merciful. They had a large command of slave labour, and would naturally employ it where the work to be done was exceptionally hard and disagreeable. Moreover, the Carthaginians, their colonists, are likely to have kept up the system, whatever it was, which they found established on succeeding to the inheritance of the Phoenician mines, and the fact that they worked them by means of slaves makes it more than probable that the Phoenicians had done so before them.[1042] When the metals were regarded as sufficiently cleansed from impurities, they were run into moulds, which took the form of bars, pigs, or ingots. Pigs of copper and lead have, as already observed, been found in Sardinia which may well belong to Phoenician times. There is also in the museum of Truro a pig of tin, which, as it differs from those made by the Romans, Normans, and later workers, has been supposed to be Phoenician.[1043] Ingots of gold and silver have not at present been found on Phoenician localities; but the Persian practice, witnessed to by Herodotus,[1044] was probably adopted from the subject nation, which confessedly surpassed all the others in the useful arts, in commerce, and in practical sagacity. CHAPTER XI--RELIGION