Rowling has said that she sees magic as a metaphor – 'a beautiful metaphor for other things in life' – and she has drawn attention to literary aspects of Harry Potter. Allusion is a crucial part of Harry Potter's literariness. Rowling turns here to the companionableness of allusion to express the experience of authorship, and it is significant that she chooses Charles Dickens to do this, for he is one of the writers whose experience of authorship relates most closely to her own. Harry Potter may also draw on Lewis's description of reading in an unspoken undercurrent to one of its magical objects: 'as if a food one had enjoyed for the taste proved one day to enables to understand the speech of birds'. Harry reads about Dumbledore's achievements on his first chocolate frog card: alchemical innovations with Nicholas Flamel, defeating Grindelwald and his 'discovery of the twelve uses of dragon's blood'.