Excerpt:
Most people probably think of salt as simply that white granular food seasoning found in a salt shaker on virtually every dining table.
It is that, surely, but it is far more. It is an essential element in the diet of not only humans but of animals, and even of many plants. It is one of the most effective and most widely used of all food preservatives (and used to preserve Egyptian mummies as well). Its industrial and other uses are almost without number. In fact, salt has great current as well as historical interest, underlying geopolitics and even the subject of humorous cartoons and poetry and useful in film-making. Sometimes, however, we need to separate the salt to get the history. And there's a lot of history to get ( 1 2 3 ). There's even a new (2002) book by Mark Kurlansky, Salt: A World History.