Scientists in Wales are studying the 13th century Red Book of Hergest, a work compiled by a dynasty of physicians from Myddfai, in hopes of finding new drugs. Scientists in Wales are studying the 13th century Red Book of Hergest, a work compiled by a dynasty of physicians from Myddfai, in hopes of finding new drugs. The book is an extensive work of over 200 plants with over 500 remedies for ailments ranging from fever to deafness. Researchers from the National Botanic Garden of Wales in Llanarthne believe that details given in the Red Book, including procedures for harvesting and processing the plants, might be vital to learning how to use such plants in modern medicine. When the Garden's research center opens this fall, scientists will use modern techniques like tissue culturing to study some of the plants used by the Physicians of Myddfai.