Salted_ A Manifesto on the World's Most Essential Mineral, With Recipes - Mark Bitterman [16]
We think we know what salt is. But whenever we try to simplify something in nature, we inevitably get it wrong. The character of an individual salt is determined by the unfathomably complex interactions of sea, land, and climate. Salt crystals offer as many variations of mineral composition, shape, size, and color as there are forms of snowflakes. Every salt bears encoded within it the human and natural environments from which it was born, and through it we can trace the lineaments of the human condition.
Salt started on earth about 5 billion years ago, when the molten planet cooled enough to support liquid water. Falling rain collected vast quantities of soluble minerals from the soil and atmosphere, slowly salting the ocean. Meanwhile, volcanic islands and undersea eruptions spewed clouds of ash into the atmosphere, where lightning bolts fried them into amino acids, the basic building blocks of proteins, and these gradually accumulated on the sea floor. Drying sea beds, tectonic and volcanic activity, sun, and rain—all churned and cooked the earth’s crust, ocean, and atmosphere for millions upon millions upon millions of years. All the while, meteors were slamming into the planet, vaporizing water and earth and salt, and low-flying comets hailed down frozen water and carbon dioxide, methane, and ammonia amid fireballs of rock and dirt. Rain washed all of it—protein, ash, meteor dust, noxious gases, everything—into the ocean, which, as you may imagine, became a very complicated place.
Some scientists believe that salts in the primordial ocean provided the organic precursors for the development of life. They think that primordial salts, superheated by volcanic activity, formed pyrroles, which are compounds found in chlorophyll (which converts sunlight to sugar in plants), and hemoglobin (which transports oxygen through blood). Without salt, there may never have been life at all. Over the course of hundreds and hundreds of millions of years of increasingly complex interactions between the sea, sun, atmosphere, and earth, molecules gained the ability to harvest light and something sprang to life. Eventually we had blueprints for life encoded in the complex molecules called DNA; eukaryotic cells formed; and a few billion years later, we have you.
Today’s oceans retain much of their primordial vitality. Every element in the earth’s crust and in its atmosphere is present in seawater. Eight elements make up ninety-nine percent of the ocean: oxygen, hydrogen, chlorine, and sodium, with considerable amounts of magnesium, sulfur, calcium, and potassium. But a laundry list of another 76 or more minerals follows, from argon to zirconium—the crystalline image of earth’s ancient, violent past.
The overall volume of dissolved matter in the ocean is staggering, enough to enrobe the entire planet in a 150-foot-thick blanket of salt, or to cover the entire land mass of the earth 500 feet deep.
SALT IN THE BODY
The cure for anything is salt water—sweat, tears, or the sea —Isak Dinesen
Chemically, our bodies are about 99 percent oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus, and the remaining 1 percent is made up of potassium, sulfur, sodium, chlorine, magnesium, and iron, and trace amounts of dozens of other elements.
One of the biggest differences between us and the ocean is that we contain only about two-thirds water by weight, with much of the remaining third built out of carbon, nitrogen, and calcium. Also, our bodies are not as saline as the ocean, so the host of ions found in seawater are not as dominant in us. Blood is about 0.9 percent salt, 77 percent of which is sodium chloride, with lesser amounts of bicarbonate, potassium, and calcium. This holds true not just for humans, but for all vertebrate animals—from fish to reptiles to mammals. But the similarities between our bodies and the ocean are otherwise striking.