Erin Connelly of the Libraries is working with other experts to identify old stains in a centuries-old medical text using multi-spectral imaging. The results of their studies suggest that the tomes were actively used in medicine and alchemy, a predecessor to chemistry.
http://www.philly.com/philly/health/science/old-medical-book-harry-potter-penn-library-stains-20180514.html Philadelphia Inquirer