One interesting theory on the cause of manic depression or bipolar disorder is that there is a super-fast biological clock located in the hypothalamus, in the center of the brain, which is actually a tiny cluster of nerves called the supra chiasmatic nucleus or SCN.
Since the release of the first novel, Harry Potter and the Philosopher's Stone, on 26 June 1997, the books have found immense popularity, critical acclaim and commercial success worldwide.
It's been 20 years since Harry Potter and the Philosopherâs Stone was first published How many Harry Potter books are there? The Harry Potter literary series spans seven books, each corresponding to a year-long period (usually Harryâs school year). In order, the books are: Harry Potter And The Philosopher's Stone