<P> There is more salt in animal tissues, such as meat, blood, and milk, than in plant tissues . Nomads who subsist on their flocks and herds do not eat salt with their food, but agriculturalists, feeding mainly on cereals and vegetable matter, need to supplement their diet with salt . With the spread of civilization, salt became one of the world's main trading commodities . It was of high value to the ancient Hebrews, the Greeks, the Romans, the Byzantines, the Hittites and other peoples of antiquity . In the Middle East, salt was used to ceremonially seal an agreement, and the ancient Hebrews made a "covenant of salt" with God and sprinkled salt on their offerings to show their trust in him . An ancient practice in time of war was salting the earth: scattering salt around in a defeated city to prevent plant growth . The Bible tells the story of King Abimelech who was ordered by God to do this at Shechem, and various texts claim that the Roman general Scipio Aemilianus Africanus ploughed over and sowed the city of Carthage with salt after it was defeated in the Third Punic War (146 BC). </P> <P> Salt may have been used for barter in connection with the obsidian trade in Anatolia in the Neolithic Era . Herodotus described salt trading routes across Libya back in the 5th century BC . In the early years of the Roman Empire, roads such as the Via Salaria were built for the transportation of salt from the salt pans of Ostia to the capital . Salt was included among funeral offerings found in ancient Egyptian tombs from the third millennium BC, as were salted birds, and salt fish . From about 2800 BC, the Egyptians began exporting salt fish to the Phoenicians in return for Lebanon cedar, glass, and the dye Tyrian purple; the Phoenicians traded Egyptian salt fish and salt from North Africa throughout their Mediterranean trade empire . </P> <P> In Africa, salt was used as currency south of the Sahara, and slabs of rock salt were used as coins in Abyssinia . Moorish merchants in the 6th century traded salt for gold, weight for weight . The Tuareg have traditionally maintained routes across the Sahara especially for the transportation of salt by Azalai (salt caravans). The caravans still cross the desert from southern Niger to Bilma, although much of the trade now takes place by truck . Each camel takes two bales of fodder and two of trade goods northwards and returns laden with salt pillars and dates . In Gabon, before the arrival of Europeans, the coast people carried on a remunerative trade with those of the interior by the medium of sea salt . This was gradually displaced by the salt that Europeans brought in sacks, so that the coast natives lost their previous profits; as of the author's writing in 1958, sea salt was still the currency best appreciated in the interior . </P> <P> Salzburg, Hallstatt, and Hallein lie within 17 km (11 mi) of each other on the river Salzach in central Austria in an area with extensive salt deposits . Salzach literally means "salt river" and Salzburg "salt castle", both taking their names from the German word Salz meaning salt and Hallstatt was the site of the world's first salt mine . The town gave its name to the Hallstatt culture that began mining for salt in the area in about 800 BC . Around 400 BC, the townsfolk, who had previously used pickaxes and shovels, began open pan salt making . During the first millennium BC, Celtic communities grew rich trading salt and salted meat to Ancient Greece and Ancient Rome in exchange for wine and other luxuries . </P>

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