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Scurvy, Scott, and understanding why something works

There’s a fantastic example of how the value of breakthrough innovation can so easily be lost in this Cautionary Tales podcast by Tim Harford. Tim tells the tale of how in the 18th Century James Lind (pictured above) became passionate about solving the problem of sailors dying on long voyages from unknown causes. Scurvy (or a lack of Vitamin C over an extended period of time) was an unknown condition at the time but Lind became the first physician to conduct a controlled clinical trial to try and find the reason why so many sailors died in terrible circumstances when at sea for long periods.

In 1747, whilst aboard a ship called the Salisbury, he selected 12 patients that were all suffering badly from scurvy (and at a similar stage of advancement), split them into pairs and gave each pair a different potential solution. One pair was given cider regularly, another pair drops of ‘elixir vitriol’ (which is actually Sulphuric acid), another sea water, another pair got two oranges and a lemon added to their diet and so on. The patients that were taking the oranges and lemons recovered very quickly, whilst those on the other treatments faired much poorer. It’s easy with hindsight for us to understand why this happened of course but in spite of the brilliance of Lind’s controlled test it took fifty years before the British Navy made lemon juice (rich in Vitamin C) a compulsory part of the sailor’s diet.

Why was this? In spite of the efficacy of his test, Lind was reluctant to recommend using oranges and lemons on long sea journeys because they were a relatively expensive solution. Even when the efficacy of lemon juice was understood, the Navy started boiling the lemon juice to preserve it, not realising that this would get rid of the Vitamin C that it contained. After this the Navy then replaced lemon juice with lime juice (hence the term ‘limeys’ to describe British sailors) because it was cheaper. Unfortunately limes contain less Vitamin C than lemons and so it’s efficacy was again much reduced.

Sadly, Lind and the British Navy had failed to understand not just the fact that lemons and oranges worked to cure and prevent scurvy, but WHY they had this effect. As Tim discusses, for years it was assumed that the positive effect came from active agents contained in the fruit rather than being a disease resulting from the omission of something essential from sailor’s diet. The tragedy is that in 1912, 165 years after Lind’s first controlled test, the lack of understanding of scurvy and it’s progression and treatment, is likely to have been a significant contributory factor to the tragedy surrounding Scott’s ill-fated trip to the South Pole.

There’s a good lesson here around breakthrough innovation. When we break new ground and are able to create new possibilities with new discoveries or big ideas we need to understand cause and effect. With a new discovery of any kind we need to understand not only what happened by WHY it happened. With a big idea we need to understand not only that it is ground-breaking but precisely HOW it is different. Otherwise we risk, underinvesting, or looking for cheaper solutions that actually don’t work, or unlearning the lessons that are before us.

Image: George Chalmers, Public domain, via Wikimedia Commons

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