How Scurvy Was Cured, then the Cure Was Lost

Yes, this really happened: scurvy was "cured" as early as 1497, when Vasco de Gama's crew discovered the power of citrus...but this cure was repeatedly lost, forgotten, rediscovered, misconstrued, confused, and just generally messed around with for hundreds of years, despite being a leading killer of seafarers and other explorers. By the 1870s the "citrus cure" was discredited, and for nearly sixty years, scurvy -- despite being cured, with scientific research to back it up -- continued killing people, including men on Scott's 1911 expedition to the South Pole. This went on until vitamin C was finally isolated in 1932 during research on guinea pigs. Self-described painter/computer guy Maciej Ceglowski gives us the absurdly fascinating story of scurvy -- a bizarre tale of science gone wrong, and a really good explanation of why you should eat a bit of citrus once in a while. (I would argue from this piece alone that Ceglowski needs to add "science journalist" to his title.)

Now, I had been taught in school that scurvy had been conquered in 1747, when the Scottish physician James Lind proved in one of the first controlled medical experiments that citrus fruits were an effective cure for the disease. From that point on, we were told, the Royal Navy had required a daily dose of lime juice to be mixed in with sailors' grog, and scurvy ceased to be a problem on long ocean voyages.

But here was a Royal Navy surgeon in 1911 apparently ignorant of what caused the disease, or how to cure it. Somehow a highly-trained group of scientists at the start of the 20th century knew less about scurvy than the average sea captain in Napoleonic times. [Robert Falcon] Scott left a [South Pole] base abundantly stocked with fresh meat, fruits, apples, and lime juice, and headed out on the ice for five months with no protection against scurvy, all the while confident he was not at risk. What happened?

... In the second half of the nineteenth century, the cure for scurvy was lost. The story of how this happened is a striking demonstration of the problem of induction, and how progress in one field of study can lead to unintended steps backward in another.

Read the rest for a highly readable, thoroughly researched history of scurvy and its treatment.

See also: our Scurvy T-Shirt ("When Life Gives You Scurvy, Make Lemonade").

(Story via

The Queen of Code: Remembering Grace Hopper
By Lynn Gilbert, CC BY-SA 4.0, Wikimedia Commons

Grace Hopper was a computing pioneer. She coined the term "computer bug" after finding a moth stuck inside Harvard's Mark II computer in 1947 (which in turn led to the term "debug," meaning solving problems in computer code). She did the foundational work that led to the COBOL programming language, used in mission-critical computing systems for decades (including today). She worked in World War II using very early computers to help end the war. When she retired from the U.S. Navy at age 79, she was the oldest active-duty commissioned officer in the service. Hopper, who was born on this day in 1906, is a hero of computing and a brilliant role model, but not many people know her story.

In this short documentary from FiveThirtyEight, directed by Gillian Jacobs, we learned about Grace Hopper from several biographers, archival photographs, and footage of her speaking in her later years. If you've never heard of Grace Hopper, or you're even vaguely interested in the history of computing or women in computing, this is a must-watch:

Why Are Glaciers Blue?

The bright azure blue sported by many glaciers is one of nature's most stunning hues. But how does it happen, when the snow we see is usually white? As Joe Hanson of It's Okay to Be Smart explains in the video below, the snow and ice we see mostly looks white, cloudy, or clear because all of the visible light striking its surface is reflected back to us. But glaciers have a totally different structure—their many layers of tightly compressed snow means light has to travel much further, and is scattered many times throughout the depths. As the light bounces around, the light at the red and yellow end of the spectrum gets absorbed thanks to the vibrations of the water molecules inside the ice, leaving only blue and green light behind. For the details of exactly why that happens, check out Hanson's trip to Alaska's beautiful (and endangered) Mendenhall Glacier below.

[h/t The Kid Should See This]


More from mental floss studios