View full lesson: http://ed.ted.com/lessons/mysteries-of-vernacular-quarantine-jessica-oreck-and-rachael-teel

Stemming from the days of bubonic plague in Medieval Europe, quarantines were originally used to prevent potentially plague-infested ships from disembarking at a port city. Jessica Oreck and Rachael Teel explain how the length of the wait, often 40 days, came to be associated with the word we use today.

Lesson by Jessica Oreck and Rachael Teel, animation by Jessica Oreck.