Salt, an Essential Commodity
Throughout history, salt (sodium chloride) has been such a precious commodity that wars were even fought over it. One of the contributing causes of the French Revolution was the high tax on salt imposed by Louis XVI. Salt was also used as a valuable medium of exchange. Moorish merchants traded salt for gold, gram for gram, and some central African tribes used slabs of rock salt as money. The English word “salary” comes from the Latin salarium (from sal, salt), referring to the early Roman soldier’s wages, part of which was an allowance of salt. The Greeks paid for slaves with salt, giving rise to the expression “not worth his salt.”
During the Middle Ages, certain superstitions developed around salt. The spilling of salt was considered to be a portent of doom. For example, in Leonardo da Vinci’s painting of the “Last Supper,” Judas Iscariot is depicted with an overturned saltcellar in front of him.*On the other hand, up until the 18th century, sitting above or below the position of the salt at a banquet table indicated one’s social rank, the honored position being above the saltcellar, near the head of the table.
From early times man learned to extract salt from natural brines, seawater, and rock salt. An ancient Chinese treatise on pharmacology deals with more than 40 kinds of salt and describes two methods of extracting salt that are amazingly similar to those used today. For instance, solar energy is used to extract salt from seawater at the largest solar saltworks in the world, which is located on the shores of the Bahía Sebastián Vizcaíno in Baja California Sur, Mexico.
Interestingly, it has been estimated that if all the oceans in the world were completely dried up, “they would yield at least 4.5 million cubic miles [19 million cubic km] of rock salt, or about 14.5 times the bulk of the entire continent of Europe above the high-water mark,” according to the Encyclopædia Britannica. And the Dead Sea is about nine times as salty as the ocean!
Modern-Day Use of Salt
Today salt continues to be a precious commodity, used for seasoning food, preserving meat, and manufacturing soap and glass, among other things. But a particularly interesting use is in the public health field. For example, in many countries of the world, salt is fortified with iodine to combat endemic iodine deficiency, characterized by goiter (an enlargement of the thyroid gland) and in severe cases by mental retardation. Also, some countries add fluoride to salt to prevent dental caries.
While salt is essential for good health