This is the Chemistree, an unorthodox Christmas tree made out of chemistry lab equipment and a bunch of different magic potions. "Those aren't magic potions." Oh I'm sorry, did you take the picture? "Well, no." So you have no way of knowing what they are, do you? "And neither do you besides the fact there's no such thing as magic potions." No such thing as magic potions?! Why you blasphemous little imp! *waving wand* I HEREBY BANISH THEE TO AZKABAN. *waits for smoke to clear* Well, go on -- and you better head straight there.
Thank to Sherry89, who agrees the best part of chemistry class was experimenting on your own when the teacher left the classroom. Right? Blue crystals + yellow potion = fire!