For example, the book reminded me of an iconic image from my boyhood: the round blue box of Morton salt which pictured a young girl with an umbrella, walking through the rain and spilling salt, with the slogan “When it rains, it pours.”  That image first appeared as part of a full page ad in the Ladies’ Home Journal in 1914, and it was intended to sell the idea that Morton’s table salt was superior to others (it had an additive that kept the salt crystals from sticking together).  I’d say the ads were effective, because a survey of 4,000 housewives in 1940 showed that 90% of them recognized the Morton brand.

On a more basic level, I knew that humans and other animals not only hunger for salt but cannot live without it. An adult human body contains about 250 grams of salt, enough to fill three or four saltshakers.  Since we are constantly losing some of this salt through bodily functions (like sweating), it is essential to replace it. 

There is more salt in animal tissues (such as meat, blood and milk) than there is in plants.  The work of archeologists has shown that among our ancient ancestors, nomadic tribes who subsisted on their flocks and herds did not eat salt with their food, but agriculturalists, feeding mainly on cereals and vegetables, supplemented their diet with salt.

Another memory I had forgotten is that my frontiersman ancestor Gideon Lincecum, in his writings about exploring Texas in the 1830s, referred to his need for salt.  He commented that whereas wild venison was tasty without the addition of salt, both fish and fowl needed it to be palatable.  In order to vary his diet while exploring, he mentioned on one occasion having “a little pocket that held a pound and a half of salt.”  He also wrote that a natural “salt lick,” where deer come to satisfy their need for salt, is a hunter’s paradise.

I learned from this book that for many thousands of years salt has been the best-known food preservative, especially for meat.  As a child I helped out when my family butchered a hog, and I recall that preserving the meat required a great deal of coarse salt, especially for the hams.

Predictably, humans have always tended to build communities around sources of salt or places where they can readily obtain it through trade.  I was surprised to learn the word "salary" comes from the Latin word for salt, because Roman soldiers were sometimes paid in salt.

Perhaps the most surprising thing I discovered is the widespread religious significance of salt.  Ancient Hebrews made a “covenant of salt” with God and sprinkled salt on their offerings to show their trust in him.  The ancient Egyptians, Greeks and Romans invoked their gods with offerings of salt and water and some scholars think this may be the origin of holy water in the Christian faith.

Morton’s now dominates the world’s salt business, but in the 1920s it was one of their competitors who published a booklet listing 101 uses for salt.  Today the US is both the largest producer of salt (40 million metric tons a year, earning over a billion dollars in sales revenue) and also its largest consumer.  Only eight percent is for food, with the largest use (51 percent) going to de-ice roads.  I wonder if global warming will have a significant impact on the salt business.

Jerry Lincecum is a retired Austin College professor who now teaches older adults to write their autobiographies and family histories.  Email him at jlincecum@me.com.