For the most part, modern medicine is a lot better than concoctions from the Middle Ages. But a recent study shows that at least one medieval remedy might have a groundbreaking application.

Christina Lee, a professor in Viking studies at the University of Nottingham, translated an Old English recipe for an eye salve out of the 9th century Bald’s Leechbook. The recipe reads:

take cropleek and garlic, of both equal quantities, pound them well together, take wine and bullocks’ gall, of both equal quantities, mix with the leek, put this then into a brazen vessel, let it stand nine days in the brass vessel, wring out through a cloth and clear it well, put it into a horn, and about night time apply it with a feather to the eye; the best leechdom.

Or, put more simply, mix equal parts garlic and another allium (onion or leek) with wine and cow bile and after nine days, apply to eye infections. Lee said the team chose the recipe "because it contains ingredients such as garlic that are currently investigated by other researchers on their potential antibiotic effectiveness."

Experts from the university's microbiology team recreated the mixture and tested it on Methicillin-resistant staphylococcus aureus, otherwise known as MRSA, a highly contagious strain of staph that is notoriously untreatable with modern antibiotics. The team was curious, but skeptical, predicting that the eye salve might show a "small amount of antibiotic activity," Dr. Freya Harrison said.

Instead, it was almost completely effective—only about one in 1000 bacteria survived. "We were genuinely astonished at the results of our experiments in the lab," Lee said in a press release.

In addition to providing insight on this difficult-to-treat infection, their findings have historical implications as well. The salve's effectiveness indicates that Anglo-Saxons relied, to some extent, on the trial and error fundamentals of the scientific method long before the discovery of bacteria.