New Layer of Ancient Greek Writings Detected in Medieval Book

At first glance, the manuscript appears to be a medieval Christian prayer book.

But on the same pages as the prayers, experts using a high-tech imaging system have discovered commentary likely written in the third century A.D. on a work written around 350 B.C. by the Greek philosopher Aristotle.

Later the writing was washed out using a solvent such as orange juice and overwritten with new text—a process known as palimpsesting.

By the 12th century, pages from five different earlier works had been erased, overwritten, and compiled into a Christian prayer book, the Euchologion—what is now called the Archimedes Palimpsest.