Lettuce – more than it seems
Harriet Wheelock

Lettuce – more than it seems


The library cataloguing project continues to move forward and has now passed the 12,000th item. Along the way, I have discovered interesting and varied information, but none more so than a pamphlet I catalogued recently on the subject of lettuce.

Most people, including me, know this foodstuff as the green leafy plant you eat in sandwiches or salads, and many others see no nutritional or taste value in lettuce at all. However the pamphlet entitled: Additional observations on the use of lactucarium, or lettuce opium; particularly in a case of cyanche laryngea or croup by Andrew Duncan (1744-1828) made me realise that there is more to this plant than a simple sandwich filler. The stems of lettuce secrete a milky fluid known as lactucarium, or lettuce opium because of its mild narcotic qualities.

The Ancient Egyptians used lactucarium as a remedy for insomnia and it is listed in numerous pharmacopoeia, for use in syrups, lozenges and as a remedy for irritant coughs. Research has since shown that the amount of morphine contained in lettuce to be negligible and as result lactucarium has faded from use.

The sleep inducing effect of lettuce was still known in the early 20th century as it is referred to in the children's story The Tale of the Flopsy Bunnies by Beatrix Potter, when the bunnies fall asleep after eating newly flowered lettuce and succumbing to its soporific effects. In the mid 1970s this supposed property of lettuce prompted a psychotropic drug used by the American hippie movement.

The author of the pamphlet, Andrew Duncan was a Scottish physician and professor at Edinburgh University. His medical education took place at Edinburgh University and St. Andrew's and he was made a Licentiate of the Edinburgh College of Physicians in 1770. He commenced his lecturing career in 1774, and founded the first free hospital in Scotland in 1776, providing free medical advice and treatment to the impoverished citizens of Edinburgh. This was later granted a charter in 1818 and became known as the Royal Public Dispensary.

In 1774, a poet named Robert Fergusson died in a workhouse where he had been committed following the development of mental health problems after sustaining a head injury. Duncan was one of Fergusson's visitors and he conceived the idea of establishing a hospital where mentally ill people could be looked after in humane conditions. His efforts paid off and in 1807, the Royal Edinburgh Hospital was built and is still in operation today.

Andrew Duncan was also one of the first people to deliver lectures on forensic medicine in Britain and he campaigned to establish a chair of medical jurisprudence in the University of Edinburgh. It seems appropriate that his son, also named Andrew who had followed him in to the medical profession was the first professor of medical jurisprudence in Edinburgh.

The Heritage centre holds a number of volumes of medical commentaries of cases which were observed by Dr. Duncan in his long career, as well as an article on medical jurisprudence and his pamphlet on the narcotic effects of lettuce. All of this material is available to research by appointment in the Heritage Centre Reading Room, please get in touch to make an appointment.

Ruth Talbot, Library Intern