Friday, July 17, 2009

Salt and the Migration of Civilizations

Salt has a very interesting history and is closely connected to the growth of migration of civilizations. Consider that it was only about 100 years ago, with the knowledge gained through modern geology, that we realized salt was common and easy to obtain. One hundred years! Prior to this modern science breakthrough, salt was considered one of the most sought-after and treasured resources in human history.

Before modern refrigeration and canning processes, salt was used to preserve food. Once large amounts of meats could be preserved with salt, empires could go on the march and feed their armies. Some of the first conquests were salt-rich regions.

Throughout the course of human civilizations many of the great cities have been built near salt mines or evaporation mining operations in coastal areas. Salt has been used as currency in ancient times, including as payment to Roman soldiers. The word salax (salt) is the base for the word ‘salary’ and this is also the beginning of the old saying ‘worth his salt’.

Cool stuff, huh? It’s amazing to study how closely the placement of powerful civilizations in history is linked geographically to salt sources.

Here’s one example of a city built on the industry of salt; Salzburg, Austria. Salzburg’s salt mines sit protected by this fortress, which was originally built for archbishops of the Roman Catholic Church. “Salzburg” translates to “Salt castle” and enormous wealth came from these mines. Not only did Salzburg have the valuable salt resource itself, but a toll was charged for all barges that passed by on the Salzach river below.

Thursday, July 16, 2009

Eat This Rock!

In chemical terms, salt is the substance produced by the reaction of an acid with a base. When the unstable metal sodium, which can suddenly burst in to flames, is combined with the deadly poisonous gas chlorine, it becomes the food staple we call sodium chloride, or NaCl, and is from the only family of rocks eaten by humans! The mineral salt is one sodium ion and one chlorine ion. It is 40% sodium and 60% chloride by weight.

I know this all sounds kind of geeky, but science is fun and edible!

Of the many different salts, the one we most enjoy eating and identify as ‘salty flavor’ is sodium chloride. Many of the other salts will convey a bitter, sour or other unwelcome taste, though they contribute value to the human diet.

So, why would a person want to eat a rock? Our bodies need it. We lose salt through body functions and we need to replace it. Chloride is essential to our respiration and digestion. The human body does not manufacture sodium but needs it to carry important nutrients, oxygen, nerve impulses and to move muscles (including the heart).

How much salt should we eat? The experts differ in opinions on how much salt a person needs to be healthy and their estimates range from two-thirds of a pound to more than sixteen pounds per year. People who live in hot climates or who do physical labor will need more salt to replace what is lost through sweating.

Believe it or not, the adult human has about 250 grams of salt in their body. That’s about 4 salt shakers worth!