I came across this in a BBC science email. The BBC's Making History radio programme has investigated the story of Angus Fiddes, a Free Church of Scotland minister, who solved the mystery of why so many of the island's babies died within the first eight days after birth. He identified neonatal tetanus as the cause, caused by birth practices which involved dressing the remains of the unbilical cord with fulmar oil that had been stored in a gannet stomach. Once that practice was ended, the deaths stopped.
But not in time to prevent the island from being evacuated in 1930 when it was no longer practical for anyone to live there. The island is now (somewhat ironically) a major seabird colony.