I was never taught this in schools, (Didn't go to school in the UK) but the information was readily available. I got most of my receipes out of an old Funk&Wagnells encyclopedia. Not just Napalm, but also Nitrocellulose, I blew up a potato after I saw The Corsican Brothers. (No, it didn't turn out like that. The acid mixture made it squishy, and it took more than a cannon fuse to detonate.)
My favorite was Thermite, because I didn't have a high-speed camera. The damage from explosives is impressive, but it's over so quick, you basically have time for a post-mortem. Thermite lasts a long long time. Flame-throwers suck, by the way. Well, technically, they blow, but they're bulky, dangerous, you get your face melted by the heat, and that's if nothing goes horribly wrong.
Don't try this at home, kids.