Nasturtium officinale, more commonly known as watercress, is one of five species within the Nasturtium genus of plants native from Europe to central Asia.
It is one of the oldest known leaf vegetables consumed by humans and a member of the Brassicaceae or cabbage family. Because it is relatively rich in vitamin C it was suggested (among other plants) by the English military surgeon John Woodall as a remedy for scurvy in the 17th century.
The disease was the scourge of the Royal Navy for decades, its effects including “skin black as ink, ulcers, difficult respiration, rictus of the limbs, teeth falling out and, perhaps most revolting of all, a strange plethora of gum tissue sprouting out of the mouth, which rotted and lent the victim’s breath an abominable odor,” according to the chaplain who sailed with Commodore George Anson during his disastrous world voyage in 1740-44.
When Captain James Cook embarked on his first circumnavigation of the globe aboard the HMB Endeavour, he was eager to ensure his crew didn’t suffer the same fate as Anson’s.
Rather than relying on Nasturtium officinale, however, he opted for another member of the Brassicaceae family, Brassica oleracea – in its pickled form known more commonly by the name Sauerkraut.
Cook also relied on malt wort and a syrup, or ‘rob’, of oranges and lemons. The Scottish surgeon James Lind first proved citrus fruits could be used to treat the disease, detailing his ideas in the 1753 book, A Treatise of the Scurvy.
In 1762, Lind’s Essay on the most effectual means of preserving the health of seamen recommended growing salad – i.e. watercress on wet blankets. This was put into practice in the winter of 1775 when the British Army in North America was supplied with mustard and cress seeds. But in general, Lind’s advice wasn’t implemented by the Royal Navy for several decades.
Cook was keen to test the latest theories, however, and by the time the Endeavour reached Tahiti – on this day in 1769 – he was becoming increasingly convinced about the success of some of these preventative remedies.
“At this time we had but very few men upon the sick list and these had but slight complaints,” he wrote in his journal. “The ship’s company had in general been very healthy owing in a great measure to the Sour Krout, portable soup and malt.”
It was “by this means and the care and vigilance of Mr Monkhouse the surgeon that this disease was prevented from getting a footing in the ship.” Indeed, Cook had only five cases of scurvy reported to him by William Monkhouse but no deaths from the disease.
Among the gentlemen aboard the Endeavour was the naturalist Joseph Banks, and from the stories he and the rest of the men had heard back in England, Tahiti (or King George’s Island, as they called it) was a paradise they didn’t want to arrive at suffering from the kind of symptoms that might dampen the enthusiasm of the reputedly amorous female islanders.
“As I am now on the brink of going ashore after a long passage thank god in as good health as man can be I shall fill a little paper in describing the means which I have taken to prevent the scurvy in particular,” Banks wrote in his journal.
He goes on to describe his daily intake of Sauerkraut and wort but despite this he was still feeling “some small effects” of the distemper.
“About a fortnight ago my gums swelled and some small pimples rose in the inside of my mouth which threatened to become ulcers,” he continued. “I then flew to the lemon juice … I took near six ounces a day of it. The effect of this was surprising. In less than a week my gums became as firm as ever and at this time I am troubled with nothing but a few pimples on my face which have not deterred me from leaving off the juice entirely.”
But in truth, Sauerkraut, watercress, wort and citrus juices were of limited value. More important was Cook’s regime of cleanliness onboard – in particular his prohibition against the consumption of fat scrubbed from the ship’s copper pans, then a common practice in the Navy.