In chapter 30, Harry makes himself pass out by casting Luminos 12 times rapidly. That could be a foothold for investigating the effects of casting magic on the human body; he could see if he can replicate the result consistently, then try it with different spells or combinations of spells and different rates of casting, and possibly other varied conditions.
In chapter 30, Harry makes himself pass out by casting Luminos 12 times rapidly. That could be a foothold for investigating the effects of casting magic on the human body; he could see if he can replicate the result consistently, then try it with different spells or combinations of spells and different rates of casting, and possibly other varied conditions.