Research Impact is a series that pulls back the curtain of IU Research, showcasing the faculty creating, innovating and advancing knowledge that improves communities and changes lives.
Schlesinger, associate professor in the College of Arts and Sciences’ Department of History at Indiana University Bloomington, is a scholar of China and the Qing Empire, and of environmental history, who studies the trades of historic global commodities such as furs, pearls and mushrooms. By studying the impact these goods have on empires, environments and markets, Schlesinger can make sense of how trade shapes human history.
Question: What is your current research focus?
Answer: I’m piecing together the global ivory trade in a way that historical texts don’t fully allow. My team and I want to reconstruct the trade on a global scale by combining textual sources with other kinds of historical evidence, including the elephant DNA and certain trace elements found in ivory. We want to create a database that brings together all of these very different types of historical sources in one place.
Q: What made you interested in pursuing this topic?
A: This research started because I found an interesting text. It was a short account of five castaways on Jeju Island by a Korean scholar 200 years ago.
The scholar documented their language in a dictionary with 103 words in it. I became enchanted with the idea of “If you could only speak 103 words to someone, what would they be?” The first words in the dictionary are “heaven,” “earth” and “human beings.” Words for directions, numbers, chopsticks, fresh water and clothing items followed. Toward the end, the dictionary listed the castaways’ words for “ivory” and “rhinoceros.”
As an environmental historian, it blew my mind. I was like, “You can only communicate 103 words to another human being, and two of them are ‘ivory’ and ‘rhinoceros’! Why would that be the case?”
The more I dove into the historical texts about the ivory trade, though, the more disappointed I became. I found too little about where the ivory carved in China came from, or about elephants themselves, or about how natural environments were changing over time as a result of the trade.
During the pandemic, when I couldn’t go to China, I felt totally at a loss. As a historian, you have to figure out the stories not being told. Then, I realized there is all sorts of historical information inside ivory, including elephant DNA — and that we had numerous historical sources right here at IU. My colleague Lynn Struve donated ivory to experiment with DNA testing at our Center for Genomics and Bioinformatics.
I also called up the Field Museum in Chicago and asked if I could do testing on their ivory carvings from China, though I warned the testing was destructive. They said I could not destroy their priceless artifacts; go figure! Lesson learned. I had to go back to the drawing board and think of a way to unlock historical information from ivory carvings in a non-destructive way.
Q: How can you collect biological information from ivory without destroying the tusks?
A: We use an XRF spectrometer, or X-ray fluorescence spectrometer. When exposed to X-rays, elements respond by fluorescing light, and each element fluoresces at a distinctive wavelength.
The spectrometer shines X-rays at ivory and carefully measures the frequency and intensity of the light that shines back. Every piece of ivory, in turn, is unique. It contains a distinctive ratio of calcium and phosphorus, for example, as well as varying ratios of trace elements, like titanium.
To what degree do these ratios represent a unique “fingerprint” for each ivory carving? And how unique are results from individual elephant populations and regions? Those are the key questions. And we’re now finding the answers by testing ivory that derives from all over Africa and Asia. We’ll see what we ultimately discover, but so far we’re excited by what we’re finding.
Q: How will this research be used by others?
A: Historians can use this data to piece together an ivory object found in a museum, where it was carved and where the elephant was living. Archaeologists doing comparable work could also find this data useful.
It could also be useful for art historians and those interested in the history of elephants and elephant biology. If we can determine where a piece of ivory derived using XRF, and can rapidly test ivory carvings without even scratching them, we could reconstruct the global ivory trade with newfound precision, from ancient times to the present. That’s our lodestar.
To get there, we need to keep testing the predictive power of this technology. We also want to build an open-access database that anyone can use, no matter who they are, and explore the interconnections among art historical, genetic and XRF-based data.
Such a database wouldn’t just be useful to historians like me. Trading ivory across borders is illegal today, and law enforcement could use the database to determine quickly where any seized tusk or carving came from. If we get this right, we might be able to help reconstruct illegal trade networks in real time.
Q: What excites you the most about your research?
Within my department, it led me to collaborate with Kalani Craig, who is a digital historian and a medievalist. I’m also now working with Daniella Chusyd, a professor in the School of Public Health-Bloomington who studies how ecological factors influence human and elephant physiology.
I’m also collaborating with Ryan Kennedy, an archaeologist who runs IU’s William R. Adams Zooarchaeology Laboratory. Another critical partner has been Doug Sanders, who was a conservator for IU Libraries but has since moved on to the Indianapolis Museum of Art Galleries at Newfield’s. It was Doug who introduced me to XRF. He’s still running tests and helping taking the lead with the analysis, as he has since the beginning.
It also led me to impressive students. Two come to mind: Sarah Muckerheide, a graduate student in anthropology, and Askar Mazitov, an undergraduate in the College’s Individualized Major Program. They’re studying an ivory sundial discovered in a 16th-century shipwreck off the coast of the Dominican Republic. I was so impressed by the rigor of their work.
This year I’m actually taking on the directorship of the Individualized Major Program, a home for students who want to create unique, multidisciplinary majors or minors and explore topics of their own choosing. I couldn’t be more excited.
We can’t easily ship ivory across borders, and we don’t want to. By building partnerships around the world, we can do this research more effectively, and on a grander scale.
Q: Why should someone unfamiliar with the history of ivory be interested in your work?
A: It turns out a lot of people own ivory, whether they’ve inherited it or received another way. It’s surprisingly ubiquitous. You’ll find ivory in private collections and in museums. Where did all this ivory come from, and why is it so easy to find? When something is embedded in ordinary people’s lives, it’s important to question why.
In the future, along these lines, I want to start a project where anyone in Indiana who owns ivory can send it to IU for destructive or non-destructive testing, depending on what they’re comfortable with. We’d run tests and document everything we could about the object and its place in the person and their family’s history. When we return the ivory object to them, we’d also give them a full write-up on what we learn.
The more everyday people can participate in this research, the stronger it will become. There’s no point in limiting this kind of research to museum artifacts.
