I guess the same way bread was made, or milk was discovered to be drinkable

I guess. Just try to see what happens, right? Maybe someone accidentally turned themself into a flea trying to test out their new potion.

Its more of chemistry than magic....

It’s basically magical chemistry. That’s why Snape is such a bad teacher. He just teaches HOW to make a potion, not WHY those ingredients combined in a specific way makes a potion.

Got it. so different plants, animal parts, and items have their own special affects, as well as the way you use them. How do they come up with the words though? There's an endless amount of words you could make, so that's where it gets really complicated. How do you know if you have to say "Selarvetia" or "Lecornico"? (Apparently I'm good at coming up with random words now, wow.)