Lasers have been used to analyze the bones of sailors who drowned when the Royal Navy warship the Mary Rose sank in 1545. The new non-destructive technique carried out by the Royal National Orthopaedic Hospital in Stanmore, North London, shows that the men suffered from rickets, shedding new light on nutrition in Tudor England.
On July 19, 1545 Henry VIII’s flagship the Mary Rose sank suddenly under mysterious circumstances. In 1982, the rediscovered ship was raised to the surface in a remarkable feat of underwater archaeology. Because the ship sank so quickly and due to the top deck being fitted with anti-boarding netting, over 400 men went down with her in the waters off Portsmouth. Thanks to the anaerobic conditions in the mud on the sea bottom, the bones of the dead were remarkably well preserved and offer new insights into the medical world of past centuries.
The study was led by Professor Allen Goodship and included the University College London, the Science and Technology Facilities Council, and the Mary Rose Trust. For the study, tibia bones from the Trust were selected that showed characteristic deformities due to rickets – a form of malnutrition caused by a lack of sunlight or vitamin D, which has recently made a reappearance in Britain. These were compared to normal tibia bones supplied by the Vesalius Centre in Bristol.
Both sets of bones were taken to the laser facility at the Institute of Orthopaedics at the University College, where they were subjected to a technique called Raman spectroscopy. This uses a single-wavelength laser beam to illuminate the test object. The scattered laser light is collected, measured, and analyzed signs of wavelength-shifted light. This spectral shift produces a distinct signature for various chemicals, forming a "fingerprint."
According to the team, the laser revealed chemical abnormalities that confirmed that the bones from the Mary Rose were indeed suffering from rickets, which indicates the poor standard of nutrition in those days, but were otherwise normal compared to modern bone specimens. The team says that the new technique may not only prove a valuable tool for studying the history of metabolic bone diseases, but also as a detection tool for modern populations.
"This is the first time that this laser technology has been used to study bone disease in archaeological human bone," says Jemma Kerns, one of the scientists on the study team. "We have identified chemical changes in the bones, without damaging them. There is strong evidence to suggest that many of the sailors had suffered from childhood rickets and we hope to apply the Raman technique to the study of modern day rickets."
The team's results were published in the Journal of Archaeological Science.