Historically, alchemy is based on the ancient belief that all matter consists of various mixtures of four basic elements: Earth, Air, Fire and Water. In current usage, any chemistry based on ancient principles rather than modern physics may be included.
Sites dealing with alchemy as an alternative form of, or an alternative to, chemistry should be submitted here. Anything relating primarily to health or longevity should go to an appropriate subcategory of http://dmoz.org/Health/Alternative/ .