Have you read Tristram Shandy, Laurence Stern's roller-coaster of a novel? If you have you may recall the conversation between Dr Slop and Uncle Toby on the significance of the number seven: the seven sacraments, the seven days of the week, the seven deadly sins, the seven wonders of the world, the seven planets and the seven plagues.
Is there magic in the number seven? Perhaps there is. I've certainly been told that seventh children have extraordinary powers, though I've been unable to verify this, never having met a seventh child. :-)
