How interesting, Caharina - I have just finished an article on leech craft after stumbling over a reference here to Bald's Leech Book. Here is my contribution.

All I can say is that I am very, very glad I don't live in the days when this was the summary of medical knowledge ;) According to google, in the year 1000, the average child have a life expectancy of 24 years. King Alfred, who was considered to have had a long reign, died when he was 49.

What is rather amazing is how often I thought of the Harry Potter books while researching the article - eye of newt and toe of frog. And a prayer!