Of the occult Vertues of things.
THere are also other vertues in things, which are not from any Element, as to expell poyson, to drive away the noxious vapours of Minerals, to attract Iron, or any thing else; and these vertues are a sequell of the species, and form of this or that thing; whence also they being little in quantity, are of great efficacy; which is not granted to any Elementary quality. For these vertues having much form, and litle matter, can do very much; but an Elementary vertue, because it hath more materiality, requires much matter for its acting. And they are called occult qualities, because their Causes lie hid, and mans intellect cannot in any way reach, and find them out. Wherefore Philosophers have attained to the greatest part of them by long experience, rather then by the search of reason: for as in the Stomack the meat is digested by heat, which we know; so it is changed by a certain hidden vertue which we know not: for truly it is not changed by heat, because then it should rather be changed by the Fire side, then in the Stomack. So there are in things, besides the Elementary qualities which we know, other certain imbred vertues created by nature, which we admire, and are amazed at, being such as we know not, and indeed seldom or never have seen. As we read in Ovid of the Phoenix, one only Bird, which renews her self.
All Birds from others do derive their birth,
But yet one Fowle there is in all the Earth,
Call'd by th' Assyrians Phoenix, who the wain
Of age, repairs, and sows her self again.
And in another place,
Ægyptus came to see this wondrous sight:
And this rare Bird is welcom'd with delight.