James Lind

James Lind (1716 in Edinburgh – 1794 in Gosport) was the pioneer of naval hygiene in the Royal Navy. By conducting what was perhaps the first ever clinical trial, he proved that citrus fruits cure scurvy. He also proposed that by distilling sea water you could obtain fresh water. Moreover he fought for the drying of ships by better ventilation, improved clothing and cleanliness of the sailors and introduced fumigaton with sulphur and arsenic. By his work he also influenced practices of preventive medicine and nutrition among British soldiers.

Years at Sea
James Lind began as an apprentice of George Langlands, a fellow of the Royal College of Surgeons of Edinburgh. In 1739 he entered the Navy as a surgeon's mate, serving in the Mediterranean, off the coast of West Africa, and in the West Indies. By 1746 he had become surgeon of HMS Salisbury in the Channel Fleet. Two years later he retired from the Navy, wrote up his MD thesis on venereal diseases and was granted a license to practise in Edinburgh.

A Cure for Scurvy
The disease scurvy is now known to be due to a deficiency of vitamin C, but in Lind's day, the concept of vitamins was unknown. Vitamin C is necessary for the maintenance of healthy connective tissue. Its deficiency causes ulcers of the lower legs and feet, bleeding, loss of teeth and hair, opening of old wounds, depression, hallucinations, blindness, and eventually death. In 1740 the catastrophic result of Anson's circumnavigation attracted attention. Of 1900 men 1400 had died, most of them allegedly from scurvy. According to Lind scurvy caused more deaths in the fleets than French and Spanish arms.

At least since 1600 it had been known that citrus fruit have an antiscorbutic effect, when a surgeon of the British East India Company recommended them, but their use wasn't widespread. Although Lind was therefore not the first to suggest citrus fruit as a cure for scurvy, he was the first to study their effect by a systematic experiment in 1747. It ranks as one of the first clinical experiments in the history of medicine.

Lind thought that scurvy was due to putrefaction of the body which could be prevented by acids; that is why he chose to experiment with dietary supplements of acidic quality. In his experiment he divided twelve scorbutic sailors into six groups. They all received the same diet, and in addition group one was given a quart of cider daily, group two twenty-five drops of elixir of vitriol, group three six spoonful of vinegar, group four half a pint of seawater, group five received two oranges and one lemon and the last group a spicy paste plus a drink of barley water. The treatment of group five stopped after six days when they ran out of fruit, but by that time one sailor was fit for duty and the other had almost recovered. Apart from that, only group one also showed some effect of its treatment.

Shortly after this experiment Lind retired from the Navy and at first practised privately as a physician. In 1753 he published A treatise of the scurvy, which was virtually ignored. In 1758 he was appointed chief physician of the Royal Naval Hospital Haslar at Portsmouth. When James Cook went on his first voyage he carried wort (0.1 mg vitamin C per 100 g), sauerkraut (10-15 mg per 100 g) and a syrup of oranges and lemons (the juice contains 40-60 mg of vitamin C per 100 g) as antiscorbutics, but only the results of the trials on wort were published. In 1762 Lind’s Essay on the most effectual means of preserving the health of seamen appeared. In it he recommended growing salad, i.e. watercress (662 mg vitamin C per 100 g) on wet blankets. This was actually put in practice, and in the winter of 1775 the British Army in North America was supplied with mustard and cress seeds. Lind also continued to advocate citrus fruit. But because he – and most other physicians – still believed that their curative effect was due to the acid, it was reasonable to substitute them with cheaper acids.

It was Gilbert Blane, who implemented citrus fruit. In an experiment in 1794 lemon juice was issued on board the Suffolk on a twenty-three week, non-stop voyage to India. The daily ration of two-thirds of an ounce mixed in grog contained just about the minimum daily intake of 10 mg vitamin C. There was no serious outbreak of scurvy. The following year the Admiralty took up the general issue of lemon juice to the whole fleet. This was not the end of scurvy in the Navy, as lemon juice was considered as a cure for scurvy and consequentially was dispensed by the ship's surgeon. Only after 1800 were the preventive qualities increasingly recognised.

Fresh water from the sea
In the 18th century sailors took along water and beer in casks and used rain water when available. According to the Regulations and Instructions relating to His Majesty's Service at Sea, which had been published for the first time in 1733 by the Admiralty, sailors were entitled to a gallon of weak beer daily (5/6 of the usual British gallon, equivalent to the modern American gallon or slightly more than three and a half litres). As the beer had been boiled in the brewing process it was reasonably free from bacteria and lasted for months unlike water kept in a cask for the same time. In the Mediterranean wine was also issued, often fortified with brandy.

For example, a frigate with 240 men, equipped with stores for four months, carried more than hundred tons of drinking water. Water quality depended on the original source of the water, the condition of the casks and for how long it had been kept. During normal times sailors were allowed to take as much water from a guarded butt as they wanted, but weren't allowed to take any water away. When water got scarce, it was rationed and rain water was collected with spread sails. Fresh water was also collected when an opportunity presented itself en voyage, but watering places were often marshy, and in the tropics infested by malaria.

In 1758 Lind discovered that the steam of heated salt water was fresh and tasted like rain water. He also proposed to use solar energy for the distillation of water. But only when a new type of cooking stove was introduced in 1810 did the possibility arise of producing fresh water by distillation on a useful scale.

Final years at Haslar Hospital
James Lind worked as senior physician of the Royal Naval Hospital Haslar from 1758-1783. He was succeeded by his son in this position. In 1794 he died at Gosport and buried in Portchester Church. He is commemorated by a plaque in the Medical School of the University of Edinburgh.