UK scientists have successfully analysed Charles Darwin’s original specimens from his historic HMS Beagle voyage, 1831 to 1836, to the Galapagos Islands, achieving the remarkable feat without opening their nearly 200 year old preservation jars.
The breakthrough, led by a collaboration between the Science and Technology Facilities Council, the Natural History Museum in London, and Agilent Technologies, demonstrates Britain’s continuing leadership in heritage science and cutting edge research.
EXAMINING 46 HISTORIC SPECIMENS
The team examined 46 specimens housed at the Natural History Museum, including mammals, reptiles, fish, jellyfish, and shrimps collected by Darwin and fellow naturalists.
Their work revealed that preservation methods varied widely depending on species and historical practice. Mammals and reptiles were usually fixed in formalin and stored in ethanol, while invertebrates might be kept in formalin, buffered solutions, or mixtures containing additives such as glycerol.
EIGHTY PERCENT ACCURACY ACHIEVED
Using the new approach, scientists correctly identified preservation fluids in around 80 percent of cases, with partial identification in a further 15 percent.
The method also determined whether jars were made from glass or plastic, offering valuable insight into how museum storage techniques have evolved over time.
PORTABLE LASER TECHNOLOGY AT THE CORE
At the heart of the project is a portable laser spectroscopy method known as Spatially Offset Raman Spectroscopy, or SORS. The technique shines laser light through a container and analyses tiny changes in wavelength when the light is reflected back, revealing the chemical composition of the liquid inside.
SORS was originally developed at STFC’s Central Laser Facility and is the same technology now used in airport scanners around the world through Agilent Technologies.
Dr Sara Mosca of the STFC Central Laser Facility said the method removes long standing risks faced by conservators.
“Until now, understanding what preservation fluid is in each jar meant opening them, which risks evaporation, contamination, and exposing specimens to environmental damage. This technique allows us to monitor and care for these invaluable specimens without compromising their integrity.”
IMPACT FOR MUSEUMS WORLDWIDE
More than 100 million fluid preserved specimens are housed in museums across the globe. For curators, knowing exactly what chemicals surround each specimen is vital for tracking deterioration and preventing damage.
The ability to analyse jars non invasively gives museums a powerful new tool to safeguard collections and intervene before serious problems arise.
TRANSFORMING THE STUDY OF NATURAL HISTORY
Wren Montgomery, research technician at the Natural History Museum, highlighted the project’s significance for the institution’s future.
“As part of NHM Unlocked, here at the Museum we can analyse jars containing specimens without opening and disturbing their integrity. This work is the next step in demonstrating the Museum’s commitment to transforming the study of natural history.”
She added that understanding storage conditions and preservation fluids could reshape how collections are cared for.
“Analysing the storage conditions of precious specimens, and understanding the fluid in which they are kept, could have huge implications for how we care for collections and preserve them for future research for years to come.”
INTERNATIONAL RECOGNITION
The study has been published in ACS Omega and featured as the ACS Editors’ Choice.
Main Image: For illustration purposes only
