Salt

Salt in period times was mostly obtained from evaporating sea water. It was also used as an item for trade and in ther preservation of foods and was considered quite valuable.

References

• http://www.wikipedia.org/wiki/Sea_salt
• Salt: grain of life / by Pierre Laszlo ; translated by Mary Beth Mader. [Chemins et savoirs du sel]. New York : Columbia University Press, c2001. ISBN 0231121989
• Salt: a world history / Mark Kurlansky. New York : Walker and Co., c2002. ISBN 0142001619