Salt is so simple and plentiful that we almost take it for granted.
In chemical terms, salt is the combination of a sodium ion with a chloride ion, making it one of the most basic molecules on earth. It's also one of the most plentiful: it has been estimated that salt deposits under the state of Kansas alone could supply the entire world's salt needs for the next 250,000 years.
But salt is also an essential element. Life itself would be impossible without it, since the human body requires salt in order to function properly. The concentration of sodium ions in the blood is directly related to the regulation of safe body fluid levels.
And while we're all familiar with the many uses of salt in cooking, we may not be aware that salt is used in some 14,000 commercial applications. From manufacturing pulp and paper to setting dyes in textiles and fabric, from producing soaps and detergents to making our roads safe in winter, salt plays an essential role in our daily lives.
Salt has a long and influential role in world history. From the dawn of civilization, salt has been a key factor in economic, religious, social and political development. In every part of the world, salt has been the subject of superstition, folklore, and warfare, it has even been used as currency.
Economics
As a precious and portable commodity, salt has long been a cornerstone of economies throughout history. In fact, researcher M.R. Bloch conjectured that civilization began along the edges of the desert because of the natural surface deposits of salt found there. Bloch also believed that the first war - likely fought near the ancient city of Essalt on the Jordan River - could have been fought over the city's precious salt supplies.
In 2200 BC, the Chinese emperor Hsia Yu levied one of the first known taxes. He taxed salt. In Tibet, Marco Polo noted that tiny cakes of salt were pressed with images of the Grand Khan and used as coins. Salt is still used as money among the nomads of Ethiopia's Danakil Plains.
Greek slave traders often bartered salt for slaves, giving rise to the expression that someone was "not worth his salt." Roman legionnaires were paid in salt - a salarium, the Latin origin of the word "salary."
Merchants in 12th-Century Timbuktu - the gateway to the Sahara Desert and the seat of scholars - valued salt as highly as books and gold.
In France, Charles of Anjou levied the "gabelle," a salt tax, in 1259 to finance his conquest of the Kingdom of Naples. Outrage over the gabelle fueled the French Revolution. Though the revolutionaries eliminated the tax shortly after Louis XIV fell, the Republic of France reestablished the gabelle in the early 19th Century; only in 1946 was it removed from the books.
The Erie Canal, an engineering marvel that connected the Great Lakes to New York's Hudson River in 1825, was called "the ditch that salt built." Salt tax revenues paid for half the cost of construction of the canal.
The British monarchy supported itself with high salt taxes, leading to a bustling black market for the white crystal. In 1785, the earl of Dundonald wrote that every year in England, 10,000 people were arrested for salt smuggling. Protesting British rule in 1930, Mahatma Gandhi led a 200-mile march to the Arabian Ocean to collect untaxed salt for India's poor.
Religion
Salt has long held an important place in religion and culture. Greek worshippers consecrated salt in their rituals. Jewish Temple offerings included salt; on the Sabbath, Jews still dip their bread in salt as a remembrance of those sacrifices. In the Old Testament, Lot's wife was turned into a pillar of salt. Author Sallie Tisdale notes that salt is as free as the water suspending it when it's dissolved, and as immutable as stone when it's dry - a fitting duality for Lot's wife, who overlooks Sodom to this day.
Covenants in both the Old and New Testaments were often sealed with salt: the origin of the word "salvation." In the Catholic Church, salt is or has been used in a variety of purifying rituals. In fact, until Vatican II, a small taste of salt was placed on a baby's lip at his or her baptism. Jesus called his disciples "the Salt of the Earth." In Leonardo DaVinci's famous painting, "The Last Supper," Judas Escariot has just spilled a bowl of salt - a portent of evil and bad luck. To this day, the tradition endures that someone who spills salt should throw a pinch over his left shoulder to ward off any devils that may be lurking behind.
In Buddhist tradition, salt repels evil spirits. That's why it's customary to throw salt over your shoulder before entering your house after a funeral: it scares off any evil spirits that may be clinging to your back.
Shinto religion also uses salt to purify an area. Before sumo wrestlers enter the ring for a match - which is actually an elaborate Shinto rite - a handful of salt is thrown into the center to drive off malevolent spirits.
In the Southwest, the Pueblo worship the Salt Mother. Other native tribes had
significant restrictions on who was permitted to eat salt. Hopi legend holds that the angry Warrior Twins punished mankind by placing valuable salt deposits far from civilization, requiring hard work and bravery to harvest the precious mineral.
In 1933, the Dalai Lama was buried sitting up in a bed of salt.
Today, a gift of salt endures in India as a potent symbol of good luck and a reference to Mahatma Gandhi's liberation of India, which included a symbolic walk to the sea to gather tax-free salt for the nation's poor.
Warfare
The effects of salt deficiency are highlighted in times of war, when human bodies and national economies are strained to their limits.
Thousands of Napoleon's troops died during the French retreat from Moscow due to inadequate wound healing and lowered resistance to disease - the results of salt deficiency.
Salt production facilities in Saltville, Va., Virginia's Kanawha Valley and Avery Island, Louisiana, were early targets of the Union Army. The North fought for 36 hours to capture Saltville, Va., where the salt works were considered crucial to the Rebel army - so crucial that Confederate President Jefferson Davis offered to waive military service to anyone willing to tend coastal salt kettles to supply the South's war effort. In addition to dietary salt, the Confederacy needed the precious mineral to tan leather, dye cloth for uniforms and preserve meat.
