Campus Currents

Cellular Detectives

Kathleen Wheeler, Barry Rock, Ellen Marlatt UNH professor Barry Rock, center, looks over wood from an 18th-century coffin with Kathleen Wheeler '81, IAC director and principal archeologist, left, and Ellen Marlatt, IAC senior researcher, in a controlled climate environment in Portsmouth, N.H.

A science lab in Nesmith Hall and the Scanning Electron Microscope facility in Kendall are unusual places for a history lesson to take place. But that's exactly what's happening as a half-dozen students peer into their microscopes for a glimpse into America's past.

The students, enrolled in "Wood Science and Technology" taught by Barrett Rock, UNH professor of natural resources, are scrutinizing samples of wood from coffins unearthed in an 18th-century "Negro Burying Ground" during a construction project last year in Portsmouth, N.H.

Independent Archaeological Consulting (IAC), a Portsmouth firm charged with recovering the eight sets of human remains and coordinating the technical and anthropological studies, contacted Rock for help.

"It's unusual to find coffin wood in such good shape from a site this old," says Kathleen Wheeler '81, IAC director and principal archeologist. The type of coffin used tells researchers about the occupant's socio-economic status.

Rock saw the project as a perfect opportunity to involve his class. Working with teaching assistant Ryan Huntley '98, students use the scanning electron microscope to try to identify the fragile, stamp-sized pieces of wood. Characteristics like color, cell-wall thickness, the presence or absence of resin canals and a microscopic feature called crossfield pitting help them identify the wood.

salt crystals Salt crystals on the coffin wood.

"I've used these techniques for grading lumber, but never for anything like this," says Russ Reiner '06, a forestry major from Dover, N.H. "It's like 'CSI,'" he says, referring to the popular TV show about crime scene investigators. Rock agrees. "Good science is detective work. Each cellular pattern in the wood has a story to tell," he says.

The wood turns out to be white pine, which was inexpensive at the time of burial, estimated to be between 1705 and 1790. The type of wood was not a surprise, says Ellen Marlatt, IAC senior researcher, but there was an unexpected a"nding. Crystals found in two samples were identia"ed with an x-ray analysis tool as sodium chloride, or table salt. "The fact that only some of the cofa"ns contained salt means the crystals are not from road salt runoff or sea water," Rock notes.

Why salt? One hypothesis, says Rock, is that the bodies may have been preserved with salt in preparation for a delayed burial. Wheeler speculates that the salt may have been placed on the chest as a sign of respect in an African tradition.

While UNH's contribution is a small piece of the puzzle, the overall goal is to a"nd descendants before the deceased are re-interred. IAC is working to match forensic DNA samples from the human remains. In some cases, such DNA material can be used to identify family lineage. It's a long shot, Wheeler says, but she's hopeful. "It would be a dream of dreams to get real names for these people," she says.

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