M AK IN G & K N OWIN G P ROJ ECT
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OLD MADE NEW
This is the result of researchers’ attempts to re-create a 16th-century recipe for making fake coral. The method relies on pine resin and “dragon’s blood”— that is, mercury sulfide—to coat sticks and other objects.
REVIVING ANCIENT RECIPES More and more, science historians are trying to understand the past by EXPERIENCING IT FIRSTHAND SARAH EVERTS, C&EN BERLIN
DEEP IN THE NATIONAL LIBRARY of
France sits a 400-year-old recipe book, its pages jam-packed with handwritten instructions for producing ancient pigments, varnishes, colored metals, and fake gems; for casting coins, cannons, and jewelry; and for doing creative—if disturbing— taxidermy that merges cats with bats. The manuscript is a rarity: Although printed recipe books were relatively common in the 16th century, this text was the equivalent of a lab notebook for an ambitious, anonymous French craftsman, someone who didn’t just collect useful recipes but actively tinkered with them, obsessively noting observations and protocol improvements in the margins. “The text is so unruly that you can’t really read the manuscript—you have to decipher it,” says Pamela H. Smith, a historian of science at Columbia University. Smith launched a project last September to transcribe, translate, and re-create recipes from a digitized version of this chaotic manual, whose banal name, “Ms. Fr. 640,” belies its enticing contents. Funded by the National Science Foundation and dubbed the Making & Knowing Project, this venture has Colum-
bia students systematically re-creating the book’s recipes as part of their coursework. Over the next few years, the plan is to compile the results of these modern re-creations in an online portal. The Making & Knowing Project is part of a new trend among science historians to focus more on the practical side of the past and less on abstract interpretations of it. Reading and interpreting texts is the bread and butter of historical research. “But it’s often hard to know what authors meant if you don’t actually try to do what they did,” Smith says. By re-creating ancient experiments in modern labs, historians can access a deeper understanding of the mind-set and experience of early scientists, alchemists, and craftspeople. Re-creating recipes is about “getting under the skin of whoever did the experiment to understand some of their tacit knowledge,” says Erma Hermens, who has helped launch one of the world’s few master’s programs in technical art history—the study and re-creation of artists’ recipes and practices—at the University of Glasgow, in Scotland. Although science historians have been reenacting old experiments here and there CEN.ACS.ORG
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since the origin of the field in the 1910s, a majority of the re-creations have been oneof-a-kind, isolated projects, and many have been focused on physics and astronomy, rather than on understanding the laboratory practices of early molecular or materials scientists. “In the past two or three years, there’s been a sudden, new interest in experimental reconstruction of ancient recipes and experiments,” says Johns Hopkins University’s Lawrence Principe, who began re-creating alchemical experiments in the 1980s, when doing so was frowned upon. “I got a lot of criticism,” Principe says of his early efforts. “People said that I was just a scientist playing around, not doing real historical work.” Fast-forward to today, and Principe’s work, along with that of William R. Newman at Indiana University, has overturned centuries-old misconceptions that alchemists were simply esoteric pseudoscientists. The science historians have shown that allegorical writings of alchemists were actually concrete instructions for making useful products such as pigments and that alchemical manuscripts form the foundation of modern chemistry. Re-creating ancient recipes has also helped those working to keep precious masterpieces from degrading. For example, replicating recipes for pigments, oils, and varnishes by cultural heritage researchers has helped clarify why some artwork is cracking, fading, or otherwise falling prey to the insults of time. These studies have also allowed researchers to develop and test interventions for preventing or mitigating artwork degradation before conservators apply them to million-dollar masterpieces. ON OCCASION, reviving an ancient recipe
has also helped improve human health. For example, inspiration for the malaria drug artemisinin was plucked from a 4th-century A.D. Chinese text. The text had suggested that extracts of sweet wormwood, a common Chinese plant, could be active against fevers. In the 1960s and ’70s, a team of Chinese scientists followed the text’s instructions and found that the extracts could cure malaria in people (see page 37). Finally, the team isolated the active ingredient and built analogs and thus was born the drug artemisinin, which is still used on patients today. No matter what historical experiment scholars are trying to re-create—whether a medicinal recipe from 4th-century China or a protocol for making artificial gems in
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16th-century Europe—the historians face common challenges. One of the biggest misconceptions about re-creating ancient recipes in modern laboratories is that doing so is easy. “Wrong,” says Joel A. Klein, one of the postdocs at Columbia who is involved in the Making & Knowing Project. “There are pitfalls at every corner.” For example, it can take months for modern scientists to successfully repeat modern experiments recorded by their contemporaries. That’s because so much is left unsaid, Principe says, even when a genuinely well-meaning scientist tries to keep a detailed account of an experimental protocol. Add to that challenge hundreds of years of evolving terminology and evolving names for starting materials, he says. And in the case of alchemists, there’s the additional challenge posed by their inten-
tional desire to make it difficult to reproduce their work as a means to protect their intellectual property. Alchemical recipes often contain “disguised ingredients and deliberate misinformation,” says Jennifer Rampling, a historian of alchemy at Princeton University. Those wishing to re-create the work of alchemists must learn that “igniting the black dragon” likely means igniting finely powdered lead, she says, or that “dragon’s blood” is mercury sulfide. EVEN WHEN A LITERAL interpretation of
a recipe is possible, sourcing the ingredients can be a challenge. In some cases, “the ingredients are just plain weird,” Columbia’s Klein says. Case in point: his search for slippery elm root. Students in the Making & Knowing Project needed the obscure root to make a binder for sand-casting metal objects. When cooked in wine, the
root produces sticky, mucuslike proteins that hold sand molds together as hot metal is poured in to form jewelry or coins. After Klein’s team tried to find the root at health food stores and online retailers, “someone at a botanical garden finally hooked us up with a giant bag of the stuff,” he adds. Ancient recipes can also call for seemingly simple ingredients, such as wine, vinegar, onions, or eggs—but sourcing these ingredients leads to other kinds of pitfalls. Researchers typically opt for organic products to avoid contaminating their experiments with modern pesticides or herbicides. But just how “authentic” must the ingredients be? To make mid-16th-century egg tempera, a common paint binder, “do we need to breed chickens with a diet consistent with 1552?” asks Leslie Carlyle, who re-creates artists’ materials at the New University of Lisbon to help understand
RE-CREATIVE SUCCESSES
Tales of ancient recipes being carried out in modern-day laboratories
EYE ON THE PRIZE “Bald’s
Leechbook,” an Anglo-Saxon medical manual, contains instructions for a concoction that combats methicillinresistant Staphylococcus aureus. scholar with a love of ancient medicinal texts at an Old Norse literature reading group. They decided to resurrect a 1,000-year-old Anglo-Saxon recipe for curing eye infections. To their surprise and delight, the pair—along with other researchers at England’s University of Nottingham—found that their re-created concoction kills the hospital superbug MRSA,
BRITISH LIBRARY BOARD
Once upon a time, a microbiologist with a penchant for ancient cultures met an English
or methicillin-resistant Staphylococcus aureus. The recipe primarily called for familiar foodstuffs, such as garlic, onion, and wine, as well as some more peculiar ingredients, such as bile from an ox. After stewing for nine days, the mixture the team created killed MRSA just as well as vancomycin, a modern antibiotic. Of the many recipes found in the ancient “Bald’s Leechbook,” the one that Christina Lee—the English scholar—and Freya Harrison— the microbiologist—zeroed in on was for styes. That’s because these eye formations are commonly caused by S. aureus, a pathogen studied by Harrison and her adviser, Steve Diggle, at the University of Nottingham. The team is now looking for pharmacologists and chemists to pinpoint the active ingredient or ingredients in the mixture. “At the end of the day, nobody’s coming out with new antibiotics, so maybe old texts are a good starting point,” Diggle says.
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The Secret To Success: Contamination Many attempts to re-create historical experiments initially fail for a variety of reasons, including challenges sourcing ingredients and difficulties inherent in following centuriesold directions. Yet when Lawrence Principe, a historian of alchemy and chemist at Johns Hopkins University, set out to make glass of antimony, a yel-
low glass touted as a medicine, he thought it wouldn’t be too difficult. “Alchemists wrote that this was rather trivial to make,” he says. “But I wasn’t even close.” Morose-looking gray lumps sat in his vessel instead of transparent golden glass. Disheartened but not defeated, Principe wondered about the source of stibnite—an antimony ore—used in the recipe he was following. It turns out that in
ADVENTURE TIME Principe tromped
through the fields outside Bologna, Italy (below), in search of an ancient quarry that held barite stones (top right) whose trace copper and absence of iron permitted the success of a recipe for making them phosphoresce (bottom right). LAWRENCE PRINCIPE (ALL)
Killing MRSA, AngloSaxon-style
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Eastern Europe, where the recipe had originated, stibnite contains 1–3% quartz, or silica. When Principe added silica to his concoction, “lo and behold it worked just fine,” he says. An even more extreme case of impurities playing a key role in the success of alchemical recipes is the so-called Bologna stone. Principe determined that to make this artificial phosphorescent material—the first of its kind—one must literally source the principal ingredient, the mineral barite, from Bologna in Italy. “Barite found just outside the city of Bologna has absolutely no iron, which is a luminescence poison, and it also contains a trace amount of copper,” Principe says. The copper is required for making the stone phosphoresce. Principe only managed to successfully recreate the recipe when he followed centuries-old directions for tracking down the barite ore in fields just outside Bologna.
A Malaria Drug Mandated By Mao During the Vietnam War, Chinese soldiers fighting for com-
safety guidelines. Instead, researchers recreating ancient recipes use anachronistic tools: They melt substances with propane torches and use electronic crucibles and kilns instead of the real McCoy. For those who value historical authenticity, using modern equipment “can be a bit disappointing,” Klein says, but it gets the job done. Even with the unwelcome luxury of 21st-century workspaces, experiments still go awry. For example, Klein recalls the time “we had molten silver rapidly discharging from a sand mold.” Trying to cast a small piece of jewelry, the Making & Knowing team hadn’t paid careful enough attention to the handwritten instructions in “Ms. Fr.
SWEET DISCOVERY Chinese
scientists searching for a new malaria remedy in the 1960s discovered a cure for the disease in extracts of the sweet wormwood plant. munist North Vietnam were dying by the thousands from malaria because the pathogen was quickly evolving resistance to chloroquine, that era’s common weapon against it. So in 1967, China’s leader Mao Tse-tung launched a secret initiative known only as “523” to find a new antimalarial agent. More than 50 laboratories and 500 scientists around the country were involved in the megaproject, including medical researcher Tu Youyou. She and her team turned to the library for inspiration, collecting 2,000 ancient recipes, looking for texts that claimed to remedy malaria-like symptoms such as fever. The team eventually hit pay dirt in a manuscript from A.D. 340 called the “Handbook
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640” that said it was important to ensure that the sand mold had thoroughly dried. That’s because as molten metal slides into a damp sand mold, any traces of leftover water turn into steam; the pressure created causes molten silver to splash back, Klein explains. This cautionary information was in the text, “we just hadn’t paid attention,” he adds. Those who re-create recipes often remark that following in the footsteps of ancient experimenters can be a humbling experience. “They were working with a deficit of principles, but the methods were extremely sophisticated. You quickly realize that what they were doing is incredibly clever,” York’s Robertson says. “We need to combat the notion that ancient and premodern people were stupid,” Klein says. “They were a lot more advanced than we give them credit for.” ◾
of Prescriptions for Emergencies.” The recipe directed the scientists to perform an extraction from the leaves of a common Chinese plant called sweet wormwood. Initially the extract was a dud. But then the researchers realized that they had been killing the active ingredient by boiling the leaves. The original text advised letting the leaves soak in cold water. When the team switched to an ether-based extraction, it struck gold: A unique chemical found in the wormwood extract—namely a sesquiterpene lactone with a peroxide group—was active against malaria (Cell 2011, DOI: 10.1016/j.cell.2011.08.024). Derivatives of the molecule were named artemisinin and are still used as a malaria drug today.
Dyeing For Black Hair dye hasn’t changed much in 2,000 years. When Philippe Walter, a chemist at the University of Pierre & Marie Curie, in Paris, followed an ancient Roman recipe for dye-
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ing hair black, he realized that modern-day Grecian Formula isn’t too much different. Walter carefully followed the instructions penned by Claudius Galen, NANO LETT.
JORGE FERREIRA
their degradation. “You can see how this could quickly spin out of control.” Re-creating ancient recipes can also be a risky proposition. Because of safety concerns, Haileigh Robertson, who studies 17th-century gunpowder experiments at the University of York, in England, won’t even try to reproduce one of famous chemist Robert Boyle’s experiments. To test whether air was needed for combustion, “Boyle rigged up a pistol in a vacuum chamber to see if the gunpowder would ignite when the pistol fired,” she says. Indeed, scholars doing reconstructions often struggle with balancing the realities of lab safety with historical accuracy. For example, “we can’t build a big charcoal fire in the lab,” Klein says, because it doesn’t exactly mesh with federal lab
OLD-SCHOOL DYE JOB Blond
hair (left) dyed black (right) using an ancient Roman recipe produces lead nanoparticles in the hair. a famous 2nd-century Roman doctor, and used lead oxide and slaked lime to darken tresses (Nano Lett. 2006, DOI: 10.1021/ nl061493u). Turns out Grecian Formula also uses lead to blacken hair, Walter notes. But the real surprise came when he peered at the hair he had dyed under a microscope. By following the ancient dye recipe, his team had created lead sulfate nanoparticles in the hair. Who knew ancient Rome had already nailed nanoscience?
