Alchemy is an art that is compiled of many practical elements and a multitude of theoretical practices. Those of us with magical blood are aware of these theoretical elements, whereas Muggles are only vaguely familiar with three practical branches of Alchemy, those three being: The Elixir of Life, turning base metals into gold, and a Universal Solvent. Even today, after centuries of experimentation, those Muggle alchemists have failed for the same reason: the don't have the magical ingredients required to succeed in such practices.
This fact is what keeps the secrets of Alchemy a closely guarded secret of our society. Certain details still remain elusive to us all, as they went to the grave with their creator. That being said, it leaves an ominous cloud still looming over this age-old study.
Like any other ancient practice, the magic behind Alchemy is much more complex than Transfiguration or Divination. It doesn't carry the same air of simplicity as memorizing an incantation and whipping your wand around. The process is precise, and one mistake can be fatal. The said processes include reading Alchemical script, brewing healing tonics and solutions or learning to focus your aura into your work.
the Elixir of Life), purely as an Educational exercise. These exercises will also include memorization of how certain substances work together and vice versa.