Page:The Works of William Harvey (part 1 of 2).djvu/618

518 are elements. It is, however, an argument of no great cogency to say that natural bodies are primarily produced or composed of those things into which they are ultimately resolved; for upon this principle some things would come out composed of glass, ashes, and smoke, into which we see them finally reduced by fire; and as artificial distillation clearly shows that a great variety of vapours and waters of different species can be drawn from so many different bodies, the number of elements would have to be increased to infinity. Nor has any one among the philosophers said that the bodies which, dissolved by art, are held pure and indivisible in their species, are elements of greater simplicity than the air, water, and earth, which we perceive by our senses, which we are familiar with through our eyes.

Nor, to conclude, do we see aught in the shape of miscible matter naturally engendered from fire; and it is perhaps impossible that it should be so, since fire, like that which is alive, is in a perpetual state of fluxion, and seeks for food by which it may be nourished and kept in being; in conformity with the words of Aristotle, that "Fire is only nourished, and is especially remarkable in this." But what is nourished cannot itself be mingled with its nutriment. Whence it follows that it is impossible fire should be miscible. For mixture, according to Aristotle, is the union of altered miscibles, in which one thing is not transformed into another, but two things, severally active and passive, into a third thing. Generation, however, especially generation by metamorphosis, is the distribution of one similar thing having undergone change into several others. Nor are mixed similar bodies said to be generated from the elements, but to be constituted by them in some certain way, solvent forces residing in them at the same time.

These considerations, however, properly belong to the section of Physiology, which treats of the elements and temperaments, where it will be our business to speak of them more at large.