how bodies are mixed and contemperated one with another.

the ancient philosophers held that the mixture of elements proceeded from the alteration of qualities; but the disciples of anaxagoras and democritus say it is done by apposition. empedocles composes the elements of still minuter bulks, those which are the most minute and may be termed the element of elements. plato assigns three bodies (but he will not allow these to be elements, nor properly so called), air, fire, and water, which are mutable into one another; but the earth is mutable into none of these.