An analysis of incense burners found in Pompeii suggested new potential trade links between the ancient Roman city and sub-Saharan Africa. Archeologists first discovered the remnants of the burnt offerings at a household shrine in the 1980s. Now, for the first time, researchers have published their analysis of the residue inside: They identified a type of resin native to tropical regions in Africa and Asia that points to Pompeii’s “links to civi…