NICE, FRANCE—Live Science reports that researchers led by Nicolas Baldovini of the Institute de Chimie de Nice have identified two molecules responsible for the unique scent of frankincense, often recognized today as “old church” smell. Frankincense comes from the resin of gum trees from the Boswellia genus, and was a key element in perfumes from Mesopotamia and Egypt dating back to the fourth millennium B.C. The chemical structures of the two new compounds, named olibanic acids, are mirror images of each other, and are found in extremely low levels in the essential oil of frankincense. The team was also able to synthesize synthetic versions of the molecules. “We patented the use of these compounds for fragrance formulation,” Baldovini said. For more on the relationship between archaeology and chemistry, go to “Mr. Jefferson’s Laboratory.”