Marius in the late 12th century wrote on what happens when various elements mix with one another though he explained how this worked in part by asserting the elements were divided out of a fundamental unity. This unity he likened to candle wax, which can be shaped into something else, but nonetheless remains wax. In the modern day we might interpret this unity to be the “fifth” element of “spirit” which unites all things and reconciles the superficially irreconcilable.

Mixtures were also dealt with the context of medieval medicine, which being founded on the four humors, were in turn rooted in ideas relating to the four elements. The medical philosophy of the time, for example, believed humans were composed of all four elements in balance. When they were not in balance, illness resulted. If they got too far out of balance, death resulted.

Just a few tidbits for you all to think about in addition. =)