"To see the world in a grain of sand" is the opening line of William Blake's "Auguries of Innocence", which is both irrelevant and impossible not to think of when you read a history of the world through a lens of salt. The author has written two other books, one about cod and the other about Basques, and the topics showcase his unique ability to turn narrow focus on one detail --a mineral, a fish, a small and mysterious people group living in isolation and speaking a language unrelated to any other in the vicinity-- into the long view of world history.
The topics intersect: salt is apparently a strategically important natural resource partly because it can be used to preserve cod. The Basques were great whalers who followed the Vikings to the Faroe Islands to fish cod so they could salt it and build their fortunes on the resulting preserved food. They may have even passed Iceland and reached Newfoundland in search of cod lands. And Mark Kurlansky is right there, letting salt (and Basques, and cod) lead you across the Atlantic Ocean, in his very accurately titled Salt: A World History.
He also takes us to ancient China, where impact drills were used to find both salt brine and (accidentally) the natural gas that could be lit to boil it down-- this around 250 B.C. He's where the Celts invented salt pork-- ham-- only to be defeated by the Romans, who claimed all the salt mines and invented salad and salaries. He's where the Anglo-Saxons peppered, as it were, their lands with saltworks, with names ending in -wich like Norwich and Nantwich. He's also where William the Conqueror destroyed these wiches to, as it were, crush rebellion and seal the conquest. The salt-destroying strategy was later used by the Northern forces to weaken the Confederacy during the Civil War-- without salt, the South could not preserve food long enough to get it to the troops. Salt was a weapon of war as late as the Indian independence from Britain, when Ghandi, instead of leading a tea party, led an illegal salt-harvesting expedition (for the same reason-- to protest unreasonable taxes and restrictions on production).
Which brings us to the geology of salt-making. It appears you can get salt two main ways: you can evaporate salty water until it precipitates out, or you can dig it out of rocky deposits that are usually found in veins, like coal. Occasionally, these salt deposits are the size of mountains, either exposed above ground or hidden by layers of other rock. Where they are exposed, of course they are highly subject to erosion; where they are hidden, the capacity to extract the mineral is limited by the weight above the deposit.
Salt mines have even become tourist attractions. They can be adventurous, beautiful, and healthful-- not only is salt a preservative, it's also a disinfectant, and people who spend time in the mines report relief from viruses and bacterial infections. For the same reason, my dentist recommends a salt rinse for irritated gums.
Salt has also motivated the construction of roads and canals, since money could only be made if large quantities of it could be gotten from where it is to where it isn't. Camels were attempted in Nevada, to the dismay of the salt miners, their other animals, and the camels themselves.
There are many kinds of salt. The color is caused by the presence of other minerals and impurities: the clay from the earth the salt evaporates on, iron oxide in Himalayan salt, minerals and even heavy metals not refined out of "natural" sea salt. There are also many different textures that people come to appreciate: the fine, even cubes of commercial table salt are great for baking, while chunkier, uneven "kosher salt" or flaky sea salt may provide a bigger "punch" of flavor. One thing's for sure-- reading this book really makes you want to eat some pretzels or popcorn. Iodine, of course, is an impurity added to salt on purpose as a public health measure, and has greatly reduced the incidence of goiter worldwide.
Salt is a recurring metaphor in the teachings of Jesus. What does salt do? It preserves and disinfects-- it prevents decay and disease. It provokes thirst and is, along with many other minerals, essential to health. It tastes good and enhances the flavor of everything it's added to. And one other thing: it cannot, in fact, lose its saltiness. It can become diluted, it can become adulterated, but sodium chloride will always retain the properties of salt. Those are the facts about salt-- make of them what you will.
