If you're a fan of pirate movies, you may be familiar with the term scurvy dog. It's a curse, typically levied at a pirate who sank below even the already lowly standards of allowed piratical behavior. What does it mean? Well, "dog" is self evident, but scurvy?

It's one of those diseases you don't hear much about anymore, but back in the 18th century scurvy was a common illness.

Imagine you're a deckhand on an 18th century British frigate. You've been at sea for months, and it's been at least that long since you've seen, let alone eaten, a nice piece of fruit. It's been stale biscuits and rum for some time now. One day you notice dark spots on your skin, and then your teeth start falling out and you start to bleed internally. Before long, you're headed straight for Davy Jones' locker.

What happened? Without citrus fruit, sailors ingested practically no vitamin C, which is important for the body's production of collagen. Collagen is fibrous substance that helps keep cells together. Without it, bones, teeth, and the body's connective tissues begin to break down. All it takes to cure and prevent scurvy is regular doses of vitamin C. Although they weren't aware of the vitamin C and collagen components, by the mid 18th century British doctors figured out that sucking on limes and other citrus fruits would keep their sailors healthy, or at least scurvy-free.

The acidity of lime juice wreaked havoc on sailors' teeth, but it was evidently a small price to pay for stopping scurvy in its tracks.