Human life has always depended on salt. Chemically, and culturally.

All animals need it for the function of blood, organs, muscles and nerves. Carnivores get it from eating other animals. Herbivores get it from salt licks and minerals in groundwater.

For millennia, humans have used salt to preserve meat—and still do today. This works because salt, in abundance, kills bacteria.

When we pack meat in salt, it draws water from the cells. Water naturally moves across cell membranes to try to reach an equilibrium of saltiness on both sides of the membrane.

This process dehydrates the meat, making it inhospitable for bacteria and parasites, which need water to live.

Culturally, salt has been equally important.

Salt-preserved meat and fish were crucial to our exploration of the globe, feeding sailors as they crossed oceans, and sustaining remote communities.

Wars were fought over salt, and access to it could influence the outcome.

As recently as the American Civil War, Union troops captured Confederate salt mines to limit their food supply and force them to the coasts to get salt—where they could be more easily attacked.

Settlers in the West often followed game trails to and from brine springs or salt outcrops. These became cattle trails, then wagon paths, then roads, sometimes even the highways of today.

Salt has literally shaped the course of human history.