With respect, sir, it sounds as if you have read a Potions textbook and quite misunderstood it. It is not the same process as that awful muggle science at all and we don't conduct their ghoulish experiments. We are civilised people. There is also far more to magic than observation. It is a skill, and a gift, and an art, and intent matters. Wizards far off in Africa or Cathay don't use the same incantations as we do, or the same magical tools, and why should they? Their traditions are different. But they are still wizards.
I do not claim to know more about your species' time travelling abilities than you do because I once read a book on the subject. I would be grateful if you would extend me the same courtesy.
[Sorry! Not only does he not understand at all, he's kind of insulted. ;) ]