Harry and anger

[alora]

No: HPFGUIDX 74520

Okay, I don't have my UK edition with me, or the American one, so 
please be patient with me.  In OotP, when Harry is in the Gryffindor 
common room studying up on potions, remember what he was reading?  
Something about a potion that causes anger.  He kept reading a line, 
drifting off, reading a line....Is it possible that someone could be 
feeding him that potion?  The first time I read it, I wondered, "Why 
is this in here?"  Maybe for future use?  Out of all of the posts 
since OotP came out, I know someone has already discussed this.  If 
you all have, please point me in the right direction! :)  

Thanks, 
Alora