Speaker 1: Welcome to brain stuff from how Stuff Works. Hey there,
Speaker 1: brain stuff, Lauren Vogel bomb here. In the seventeenth century,
Speaker 1: a return of plague, also known as the Black Death,
Speaker 1: killed about one million people in France. Oddly enough, the
Speaker 1: residents of Paris were largely unaffected, despite having the same
Speaker 1: rat problem as any other large city. The rodents carried
Speaker 1: fleas that bore the plague. After the plague killed the rats,
Speaker 1: the fleas often hopped onto human hosts. In this way,
Speaker 1: the plague spread like wildfire, snuffing out life after life.
Speaker 1: The Parisian's miraculous avoidance of the plague could have remained
Speaker 1: one of history's mysteries, but author Tom Nielan squeezed a
Speaker 1: potential explanation out of seemingly desperated events. A purveyor of
Speaker 1: rare books, Neilon is not only a connoisseur of history,
Speaker 1: but of the impact that condiments and food stuffs may
Speaker 1: have had on antiquity. His new book of Food Fights
Speaker 1: and Culture Wars follows these sometimes surprising influence food has
Speaker 1: had throughout history. Neilan says health food were intimately connected
Speaker 1: for the longest time. Early collections of recipes frequently mixed
Speaker 1: medical and cookery receipts as recipes were called, so it's
Speaker 1: easy to start to conflate them when you're studying the
Speaker 1: period and old cookbooks. Even after they started to separate,
Speaker 1: the Renaissance Book of Secrets kept elements of food and
Speaker 1: home remedies together for centuries longer in the case of Paris,
Speaker 1: and it's largely unscathed population. In the sixteen hundreds, the
Speaker 1: timing of a lemonade trend and the timing of a
Speaker 1: plague coincided, and Nilan wondered whether it was more than
Speaker 1: a coincidence. Up until the sixteen hundreds, lemons had been
Speaker 1: a rare and expensive fruit. All the lemon trees had
Speaker 1: been cultivated throughout Europe and Asia in the preceding decades,
Speaker 1: and a few recipes using lemon as an ingredient had emerged.
Speaker 1: The citrus fruit was a little used in England and France,
Speaker 1: both because of cost and the notion that eating raw
Speaker 1: lemons was harmful. Then an increase in trade and a
Speaker 1: fascination with lemonade popularized the tart fruit, so that by
Speaker 1: the mid sixteen hundreds it was widely available. Nilan explained,
Speaker 1: during the Renaissance, lemons had been bread and domesticated enough,
Speaker 1: and trade had become organized enough that lemons were sufficiently
Speaker 1: inexpensive in the mid seventeenth century to import in bulk.
Speaker 1: Lemonade was all the fashion in a number of cities
Speaker 1: in Italy at the time, especially Rome, and the fad
Speaker 1: spread from there. The cookbook liquis ineur Francois, published in
Speaker 1: sixteen fifty one and written by chef Francois Pierre Lavarenne,
Speaker 1: is considered one of the founding texts of modern French cuisine.
Speaker 1: It included a recipe that combined lemon juice, water and sugar.
Speaker 1: This recipe also contributed to the popularity of lemonade in France.
Speaker 1: And with all this lemonade came lots and lots of
Speaker 1: lemon peels. Lemon peels were everywhere, in the garbage, in
Speaker 1: the gutter, in the river, anywhere that you could find rats.
Speaker 1: It was this fortuitous combination of rats and lemon peels
Speaker 1: that may have stopped the spread of plague. Lemon peels
Speaker 1: contain lemoning, a natural ingredient that kills flea larvae and
Speaker 1: adult fleas. The more people that made lemonade and discarded
Speaker 1: the lemon peels, the more the rats nibbled on the peel,
Speaker 1: inadvertently ingesting, lemoning, and killing fleas and their eggs. Neil
Speaker 1: And says the lemoning disrupted the spread of fleas from
Speaker 1: the rats to people. Because the plague kills so quickly,
Speaker 1: the fleas needed to move from rats to people back
Speaker 1: to rats over and over again to keep it going
Speaker 1: as their hosts expired. Lemoning, a flea killer that is
Speaker 1: still broadly used in pet treatments, killed the fleas and
Speaker 1: prevented the chain from getting going. At the time and
Speaker 1: four centuries after the plague subsided, the survival of Parisians
Speaker 1: was attributed to an airing out of goods blankets, bedsheets,
Speaker 1: clothes that had been quarantined. At the time. It was
Speaker 1: mistakenly believed that the illness traveled by air, when it
Speaker 1: was really the rats and fleas traveling with the quarantined
Speaker 1: goods that were at the root of the plague. If
Speaker 1: not for Parisians love of lemonade, many more may have
Speaker 1: met a tragic end. Today's episode was written by Laurie L.
Speaker 1: Dove and produced by Tristan McNeil. For more on this
Speaker 1: and lots of other lemony fresh topics, visit our home planet,
Speaker 1: how stuff dot com