Our appetite for salt and the meanings we attach to it have linked the ages. Salt literally gives us life, and reminds us of the origins of all life in the primordial sea. It has motivated the pious, the warlike, the superstitious and the revolutionary. It has shaped history and inspired storytellers, artists and cooks. It is a commodity, a "cure" and a medium for artistic carving. Although it is essential to many modern industrial processes, the basic methods of producing salt haven't changed for centuries boil, evaporate, mine. The human body contains about four ounces of salt. Without enough of it, muscles won't contract, blood won't circulate, food won't digest, the heart won't beat. But scientists disagree over how much is too much. For years many researchers have claimed that salt threatens public health by contributing to high blood pressure. Recently, though, other researchers have begun to rehabilitate salt's reputation, claiming there's no reason for doctors to recommend reducing sodium intake for people with normal blood pressure. In fact, doctors at one hospital have discovered that a treatment for chronic fatigue includes salt supplements and plenty of pickles and other salty foods.