This is a re-run of a popular November 2006 article because of the imminent arrival of the movie this week of the Half Blood Prince. The article was written before the publishing of the last book in 2007 and I have left the speculations in that I made at the time.

Any magician can use the material in the Harry Potter books, though the visual results are not Hollywood fireworks but changes of conscious state, which is the aim of spells. Here we go.