Sometimes sayings stick. Take for instance these two often-used quotes: "The salt of the earth and variety is the spice of life."

"Ye are the salt of the earth," Jesus told his disciples during the Sermon on the Mount, one of the best known teachings of his ministry. Jesus used salt as a metaphor to emphasize to his disciples how important they were to his ministry. Two thousand years later, we use the expression to refer to someone of great value or importance.

"Variety is the spice of life" is usually attributed to the British poet William Cowper (1731-1800). "Variety's the very spice of life That gives it all its flavor" is from his multi-volume poetic work The Task (1785), Book II, "The Timepiece." Here, again, a metaphor was used to compare the ability of spices to flavor food to the way different experiences can make life interesting and fun.

That's the role salt and spices have played throughout the ages. Acting in consort, they have no equal in brightening food or the human experience.

The history of salt

A composite image of engravings depicting the layers of the Wieliczka Salt MineA composite image of engravings depicting the layers of the Wieliczka Salt Mine in Poland around 1645. (Photo: Willem Hondius/Kpalion/Wikimedia Commons)

Table salt — sodium chloride or NaCl to chemists — comes from two primary sources: seawater and mineral deposits known as rock salt. Salt has been intertwined with seasoning food, health and the development of civilizations throughout human existence. Possibly the earliest writing on pharmacology, for instance, the Peng-Tzao-Kan-Mu published in China 4,700 years ago referenced more than 40 kinds of salt.

Cities have been created or have risen to prominence because of salt. Humans followed the animals seeking food and salt. The trails they created became roads along which people settled, creating towns and cities and then nations. Europe's earliest known town, Solnitsata in present-day Bulgaria, was built around a salt production facility. Salt helped to create empires and destroyed some of them. Poland used its salt mines to develop a vast kingdom in the 16th century only to see the Germans destroy it when they brought in sea salt, which is considered more valuable than rock salt. Christopher Columbus and Giovanni Caboto destroyed the Mediterranean trade by introducing the New World to the market.

The Sermon on the Mount is hardly the only reference to salt in the Bible. In fact, there are 32 references to salt. In the Old Testament, Lot's wife was turned into a pillar of salt because she disobeyed the angels and looked back at the wicked city of Sodom. Covenants were often sealed with salt.

An illustration depicts the destruction of Sodom and Lot and his daughters escaping.An illustration depicts the destruction of Sodom and Lot and his daughters escaping. Lot's wife (center) was turned into a pillar of salt. (Photo: Sibeaster/Wikimedia Commons)

Some words and expressions we use frequently are derived from salt. The words "soldier" and "salary" have their roots in ancient Rome when Roman soldiers were sometimes paid in salt, salarium argentum. A soldier's salary was cut if he "was not worth his salt," a phrase that came into being because the Greeks and Romans often bought slaves with salt. The word "salad" also has it origins in Roman times and comes from the Roman's use of salt to flavor leafy greens and vegetables.

Salt has long been the source of superstitions. The widespread belief that spilling salt brings bad luck is believed to have originated in the painting of "The Last Supper" in which Leonardo DaVinci placed a spilled salt bowl in front of Judas Escariot, the betrayer of Jesus. Superstition still holds that if someone spills salt they should throw a pinch of it over their left shoulder because the left side was thought to be sinister, a place where evil spirits tended to congregate.

Salt was once associated with social symbolism. As late as the 18th century, guests at elaborate dinner parties were ranked by where they were seated in relation to the saltcellar. The host and the most-favored guests sat at the head of the table above the salt. People who sat the furthest from the host, below the salt, were considered to be of lesser consequence.

Salt has played various roles in solidifying or dissolving governments and even in the discovery of continents. The French government for centuries not only forced its people to buy all their salt from royal depots but forced them to pay a high tax for it as well. The tax was such a major grievance that it helped ignite the French Revolution. When Europeans arrived in the New World, the first people they saw were harvesting sea salt. During the American Revolution the British tried to deny salt to the colonists. Salt played a key role in the U.S. Civil War because part of the Union's strategy was to cut off salt supplies to Confederate troops.

Baked soft pretzel on a cooling rackOur bodies need salt, but we often don't get them from the best sources. Then again, who could deny the lure of a fresh soft pretzel? (Photo: Marie C Fields /Shutterstock)

Salt has been used as a food preservative throughout human history. While our bodies need salt, the Centers for Disease Control and Prevention have called reducing consumption of salt "a national priority." Even though there are skeptics about the evils of salt, the CDC says too much salt can increase blood pressure and raise the risk for health problems such as heart disease and stroke. More than 40 percent of U.S. sodium consumption can be attributed to these 10 food groups, according to the CDC:

  • Breads and rolls
  • Cold cuts and cured meats
  • Pizza
  • Poultry (fresh and process)
  • Soups
  • Sandwiches (such as cheeseburgers)
  • Cheese
  • Pasta dishes
  • Meat dishes (such as meatloaf with tomato sauce)
  • Snacks (such as chips, pretzels and popcorn)

The history of spices

It's easy to take for granted the rows of simple spice jars neatly lined up in alphabetical order in the grocery story aisle. If they could talk, though, they would tell a not-so-simple story of the time when spices were anything but commonly available and inexpensive.

The spice trade was once the world's biggest industry and in many ways helped to create the modern world in which we live. The story of spices begins more than 4,000 years ago in the Middle East with Arabic spice merchants.

An illustration of a caravan on the Silk RoadAn illustration of a caravan on the Silk Road in 1380. (Photo: Cresques Abraham/Wikimedia Commons)

At first, camel caravans brought spices to the Mediterranean region mostly along the Silk Road trading route from the ancient Chinese capital of Chang'an, now Xi'an, south to India, across present-day Afghanistan and Pakistan and on to the eastern Mediterranean. The merchants ensured high prices for spices by creating a mystery about their origins and telling fantastic tales about how they were harvested.

As sailing ships replaced the camel caravans and the spice trade grew into the world's biggest industry, many groups sought to control the market for spices. Eventually, Venice became the primary port for spices destined for western and northern Europe. Because Venice controlled the entry and distribution of spices, Venetian merchants were able to charge such high prices that even the wealthy had trouble affording them.

The European Age of Discovery changed that in the 15th century. With improvements in navigation capabilities that enabled longer and longer sea voyages, rich entrepreneurs began sending out explorers in hopes of circumventing the Venetian control of the spice trade. Many were not successful, but some explorers found new lands and their treasures. We owe the term "chile peppers" to one of them. When Christopher Columbus found America instead of India, among the new foods he found were chiles, which he called peppers.

A painting shows Vasco da Gama leaving Portugal to sail around the Cape of Good HopeA painting shows Vasco da Gama leaving Portugal to sail around the Cape of Good Hope in 1497. (Photo: Alfredo Roque Gameiro /Wikimedia Commons)

When the Portuguese sailor Vasco da Gama became the first person to round the Cape of Good Hope in Africa, his success led to bloody conflicts with the Spanish, English and Dutch for control of the spice trade. The popularity of spices rose with the rise of the middle class during the Renaissance. As European nations expanded they found themselves in a 200-years-long war between the 15th and 17th centuries over the Indonesian Spice Islands.

American businessmen joined the spice trade in the 18th century. Instead of working with established European companies, though, they dealt directly with suppliers in Asia. America also made a new contribution to the spice world when Texas settlers created chili powder as an easy way to make Mexican dishes.

With new and now wide-open trade routes that led to bringing not just spices but spice plants around the world, the price of spices tumbled and wealthy monopolies crumbled. While spices lost their exotic allure that once made them as valuable as jewels and precious metals, they retained something else of great value. The ability to transform the smell, tastes and allures of food.

Next in the occasional series on food that changed the world: wheat!

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