Bringing the past to the nose

NYTIMES - Anxiety sweat. Horsehair. Wet grass and soil after a rain. Sulphuric compounds from gunpowder. Eau de cologne containing rosemary, bergamot and bitter orange. A touch of leather.

This might have been what Napoleon's retreat from the Battle of Waterloo in 1815 smelled like. At least, these are some of the elements that Ms Caro Verbeek, an art historian and olfactory researcher, tried to incorporate when she was reconstructing the smell, in partnership with perfumer Birgit Sijbrands, scent designer Bernardo Fleming of International Flavors & Fragrances and the Rijksmuseum in Amsterdam.

"Wars are extremely smelly," she said. "Soldiers don't write about their injuries as much as they write about the terrible sounds and smells. So we know more about them."

We also know that it had rained the night before the battle, that anxiety sweat smells different from normal sweat, and that there were thousands of horses on the field. And we know the ingredients of Napoleon's perfume - he wore litres of it every day and carried a bottle in his boot.

These were some details Ms Verbeek relied on for the reconstruction, as part of a project called In Search of Lost Scents. The scent is offered in the Rijksmuseum as part of tours - on strips of paper or in a necklace with tiny pumps - alongside Jan Willem Pieneman's 1824 painting of the scene.

In the growing field of smell research, scientists, artists, historians and cultural heritage specialists are coming together to work on what is perhaps the trickiest sense to preserve. Some are working on trying to conserve the smells of our times. Others, like Ms Verbeek, are working on reviving and reconstructing some of the lost scents.

These are some of the areas that Odeuropa, an international research consortium on olfactory heritage that was recently awarded a 2.8 million euro (S$4.5 million) grant, is focused on studying.

Ms Inger Leemans, a cultural heritage professor and project leader of Odeuropa, said, "We're also asking, what are the fragrant places of our countries, or Europe?"

"We're losing them fast, of course, because time never stops, but is it valid to try to safeguard those places or reconstruct them?" she said. "How do you bring the past to the nose?"

History is rife with smells that we will never be able to reclaim. Despite the detailed efforts of Ms Verbeek, we will never really know what the Battle of Waterloo smelled like. We may not even be able to recapture the smells of our childhoods.

Many scents that are already vanishing include mothballs, burning piles of leaves in autumn, typewriter ribbons or the early formulas of sunscreen. And unlike, for instance, colour or music,smell is not broken as easily into universally accepted components.

Although technology has made it easier to isolate the chemical compounds of a smell, odours are also highly context dependent.

But preserving smell requires more than just olfactory data. Ms Cecilia Bembibre, a researcher at the Institute for Sustainable Heritage at University College London, is working toward a systematic means of archiving smell, using a mix of chemistry and more qualitative tools.

She has done this for the smell of old books. The first step is to seal the book off and allow the smell to concentrate for several days. Then, a technique called gas chromatography-mass spectrometry is used to separate and identify each chemical compound to create something like a recipe, or a template for historians. She also interviews volunteers and asks them to experience the smell and describe it.

The field of scent research is gaining recognition and funding internationally, but smell has long been less studied than the other senses. "It's gaining ground, but it's a bit of an oddity," said Ms Bembibre.