“Scott and Scurvy: How the Cure for Scurvy Was Lost”, 2010-06-03 ():
[Scott’s Antarctic expedition in 1911 was plagued by the disease scurvy, despite its having 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.” How it all went wrong would make a case study for a philosophy of science class.
The British Admiralty switched their scurvy cure from lemon juice to lime juice in 1860. The new cure was much less effective, but by that time advances in technology meant that most sea voyages were so short that there was little or no danger of scurvy anyway. So poor Scott’s expedition, as well as applying ‘state-of-the-art’ (ie. wrong) cures, were falling back on a ‘tried-and-true’ remedy that in fact had been largely ineffective already for 50 years… without anyone noticing.]
An unfortunate series of accidents conspired with advances in technology to discredit the cure for scurvy. What had been a simple dietary deficiency became a subtle and unpredictable disease that could strike without warning. Over the course of fifty years, scurvy would return to torment not just Polar explorers, but thousands of infants born into wealthy European and American homes. And it would only be through blind luck that the actual cause of scurvy would be rediscovered, and vitamin C finally isolated, in 1932.
…So when the Admiralty began to replace lemon juice with an ineffective substitute in 1860, it took a long time for anyone to notice. In that year, naval authorities switched procurement from Mediterranean lemons to West Indian limes. The motives for this were mainly colonial—it was better to buy from British plantations than to continue importing lemons from Europe. Confusion in naming didn’t help matters. Both “lemon” and “lime” were in use as a collective term for citrus, and though European lemons and sour limes are quite different fruits, their Latin names (citrus medica, var. limonica and citrus medica, var. acida) suggested that they were as closely related as green and red apples. Moreover, as there was a widespread belief that the antiscorbutic properties of lemons were due to their acidity, it made sense that the more acidic Caribbean limes would be even better at fighting the disease.
In this, the Navy was deceived. Tests on animals would later show that fresh lime juice has a quarter of the scurvy-fighting power of fresh lemon juice. And the lime juice being served to sailors was not fresh, but had spent long periods of time in settling tanks open to the air, and had been pumped through copper tubing. A 1918 animal experiment using representative samples of lime juice from the navy and merchant marine showed that the ‘preventative’ often lacked any antiscorbutic power at all.
By the 1870s, therefore, most British ships were sailing without protection against scurvy. Only speed and improved nutrition on land were preventing sailors from getting sick.
…In the course of writing this essay, I was tempted many times to pick a villain. Maybe the perfectly named Almroth Wright, who threw his considerable medical reputation behind the ptomaine theory and so delayed the proper re-understanding of scurvy for many years. Or the nameless Admiralty flunky who helped his career by championing the switch to West Indian limes. Or even poor Scott himself, sermonizing about the virtues of scientific progress while never conducting a proper experiment, taking dreadful risks, and showing a most unscientific reliance on pure grit to get his men out of any difficulty.
But the villain here is just good old human ignorance, that master of disguise. We tend to think that knowledge, once acquired, is something permanent. Instead, even holding on to it requires constant, careful effort.