Salt (Sodium Chloride)
by Tom Rood, Master Gardener
Cornell Cooperative Extension

After writing about pepper for last week's column it seemed appropriate to write about its table companion. Salt and pepper are on just about every table in the country. The more research we did on common table salt the more we learned that it is all around us if we were only able to slow down long enough to look. We knew pepper had a colorful history but what we uncovered in our research on table salt boggles the mind. Salt after all is a very common earth ingredient being composed of two common earth elements, sodium and chlorine.

Sodium is an unstable metal that readily combines with poisonous chlorine gas to produce sodium chloride (NaCl) which everyone knows as common table salt. Reportedly it has over 14,000 uses but I suspect that number to be far lower than reality. Up until 100 years ago, salt was a medium of exchange even being used as a substitute for money. Historically salt was one of the most sought after commodities in history.

Water vapor, evaporated by the heat of the sun from the earth's massive oceans, fell as rain upon the landmasses. Over eons of time, the rain dissolved the earth and rock in minute quantities. This has been going on for few billion years. Huge masses of mountains have been worn away, dissolved if you will, and carried away in mountain streams and rivers to be deposited into the world's oceans. Sodium is the 7th most common earth element so it is not hard to understand how the oceans became laden with dissolved salt as well as many other minerals. Even after all these billions of years, our oceans are so vast that seawater contains on average only 2.5 to 3 percent salt.

Most, if not all, sodium chloride came from evaporated seawater. Great beds of underground salt formed when prehistoric seas evaporated from rising landmasses due to continental shifts. These beds were later covered with sediment some times thousands of feet thick as in our own Finger Lakes underground salt fields. As a side note, the Mediterranean Sea contains no real outlet, discounting the Suez Canal. Yet the current flowing from the Atlantic through the Straight of Gibraltar runs around 6 to 8 knots in speed. This is faster than most folks can row a boat. If there is no outlet, where does the water go that runs into the Mediterranean Sea? The answer is the water evaporates into the atmosphere. When one thinks about the amount of water evaporating from all the world's oceans, on a daily basis, we begin to get a handle on the forces of nature.

There are generally four sources of salt. The oldest was the discovery of salt beds close to the earth's surface. These were left over from evaporated prehistoric seas and mined for centuries as a trade item. The second source, first discovered by the Chinese, was that brine wells could be mined using bamboo tubes lowered into them. The tubes filled with brine and a leather patch held the brine in while the tubes were raised to the surface. The water in the brine was evaporated either by heat from fires or the sun. The resulting salt was heavily taxed which helped raise the necessary funds to finance centuries of defensive and offensive warfare. Indeed, this method of mining salt is still in use today here in the Finger Lakes only on a much larger scale and with modern technology.

The third method of salt retrieval is deep mining where a shaft is sunk down a few thousand feet in which miners and mining machinery are lowered. Mined salt is raised to the surface. This was done at the now closed Morton Salt mine in Himrod and still is done near Cayuga Lake as well as other parts of the state. The fourth method is the flooding of shallow beds with seawater and letting the sun evaporate the water. The salt left behind is scraped away and the process repeated over and over.

When the concentration of salty water, through evaporation, reaches 26 percent, salt crystals will begin to precipitate out. Salt often surfaces as in brine springs, rock salt or any available salt for licking. Some times deep holes, almost caves, were formed by constant wild animal licking which is where the term salt licks came from. Animals first discovered the licks and formed trails to them. Native Americans, and later European settlers, made increasingly wider paths to the licks. The paths became roads, which ended at a known source of salt first found by the wild animals. Villages would spring up around these sources of salt. A large salt lick near Lake Erie had a wide road made by local buffalo herds and the village began there became Buffalo, NY.

In 875, the Basques followed the Vikings into the North Atlantic and discovered the Atlantic Cod fishing grounds. Basques were familiar with the salted fish and its importance as a staple food in former Roman controlled countries. Putting their knowledge of the use of salt in the preservation of meats and fish, they found a gold mine of world class importance. The white flesh of the bottom feeding cod is almost devoid of fat. Fat resists the absorption of salt. The highly marketable commodity soon began appearing stacked by the wagonload and stiff as slab wood being hauled over roads even in warm weather. All the salted fish needed was to be soaked in fresh water for a day or more before use.

Salt is essential to human life. The body contains approximately 250 grams of salt or enough to fill 3 or 4 salt shakers. But our bodies are constantly loosing salt through normal body functions as excretion and perspiration. It needs to be replaced. Unfortunately the tendency to over replacement is a real health problem. Estimates of the body's need for salt wildly range from 2/3 of a pound annually to over 16 pounds annually. I for one can not imagine consuming over one pound of salt per month.

One of the troubles in controlling our salt intake is that food processors use enormous amounts of salt to make their products more palatable to us consumers. Labels often list sodium content as high as 1000mg per serving. If my math is correct, that runs close to a level teaspoon of table salt per serving, which often is only one cup or eight ounces. Often multiple servings are listed on the package. If a package or bottle has more than an average eight ounce serving, they will list the sodium content for one serving. If we unsuspecting consumers eat or drink the whole product, we will get multiple doses of sodium.

We've become so accustomed to salt that foods without it seem not very tasty. Once we learn to wean ourselves away from all this additional salt, our taste buds become sensitive to salt and cause us to shy away from foods containing an excessive amount. Some sources say that normal foods contain enough natural salt that we do not have to add salt to maintain our body's need for it. That argument may turn out to be taken as a grain of salt. In the meantime, we should all be aware of just how many grains of salt we are taking.

To learn more about the interesting history revolving around salt, the Penn Yan Library has a book "Salt, a World History" by Mark Kurlansky. I found it fascinating reading. For all your lawn and garden questions call the Master Gardeners at the Cooperative Extension office 315-536-5123 leaving your name, question, phone number and a time we may return your call with the results of our research. If you are interested in becoming a Master Gardener, a new class will be forming in January. Call the Extension office for details.