Research reveals Middle Ages' dirtiest books

New research by experts at St Andrews University in Scotland reveals the reading habits of medieval people by determining accumulations of dirt on each page.

Dr. Kathryn Rudy used a machine called a densitometer to discover which pages were most read by the amount of dirt accumulated on them. Among the dirtiest pages were found to be a prayer to St. Sebastian, whose arrow wounds resembled bubonic plague. Dr. Rudy also found that pages at the beginning of the book were dirtier, leading her to believe that readers lost interest or fell asleep.