By analyzing charred scrolls that were burnt and buried by the eruption of Mount Vesuvius in 79 B.C.E., researchers have determined that the Romans wrote with metallic ink—an innovation thought to have originated several centuries later in the Middle Ages, according to a paper published today in the Proceedings of the National Academy of Sciences. The eruption buried the nearby town of Herculaneum in a deep layer of superhot ash and instantly charred the papyrus scrolls of a wealthy Roman, preserving the only known complete library from ancient times. But when the scrolls were discovered in the 18th century, they were so brittle that any attempt to unroll and read them risked turning them into ashes. Recently, scientists used a particle accelerator in Grenoble, France—a tool developed for high-energy physics experiments—to x-ray the carbonized scrolls, revealing the letters inside. The new results show not just the shapes of the letters, as seen in the left hand image, but also that they were written with leaded ink, which fluoresces in the right hand image. Archaeologists had thought that the Romans used carbon-based ink from charcoal. If other scrolls from Herculaneum were written with lead-laced ink, knowing exactly what to look for could make the job of scanning and actually reading longer stretches of the carbonized lumps of papyrus easier.