"he grasped a snake"
by cm

Creative Commons AttributionCobra - Credit: Saleem Hameed
 Snakes play an important part in alchemy.  This stems in part from powerfully transformational properties of snakes' venom, and also from their ability to slough off their old skin.  Snakes lie immobile and dull for a time, and then emerge glistening new, giving an impression of immortality and eternal youth.

Benzene Ouroboros
Public DomainBenzene Ouroboros
The ouroboros, a central symbol in alchemy, is a dragon or snake with its tail in its mouth.  The German organic chemist August Kekulé attributes his breakthrough on the ring structure of benzene to a dream about an ouroboros.  Arthur Koestler called it "probably the most important dream in history since Joseph's seven fat and seven lean cows".