The Philosophy of Natural Magic, by Henry Cornelius Agrippa, L. W. de Laurence ed. , at sacred-texts.com
There are also other virtues in things, which are not from any Element, as to expel poison, to drive away the noxious vapors of minerals, to attract iron
or anything else; and these virtues are a sequel of the species and form of this or that thing; whence also they being a little in quantity, are of great efficacy; which is not granted to any Elementary quality. For these virtues, having much form and little matter, can do very much; but an Elementary virtue, because it hath more materiality, requires much matter for its acting. And they are called Occult Qualities, because their causes lie hid, and man's intellect cannot in any way reach and find them out. Wherefore philosophers have attained to the greatest part of them by long experience, rather than by the search of reason: for as in the stomach the meat is digested by heat, which we know, so it is changed by a certain hidden virtue which we know not: for truly it is not changed by heat, because then it should rather be changed by the fire-side than in the stomach. So there are in things, besides the Elementary qualities which we know, other certain imbred virtues 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 Phœnix, one only bird, which renews herself:
And in another place—
Long since Matreas brought a very great wonderment upon the Greeks and Romans concerning himself. He said that he nourished and bred a beast that did devour itself. Hence many to this day are solicitous what this beast of Matreas should be. Who would not wonder that fishes should be digged out of the Earth, of which Aristotle, Theophrastus, and
[paragraph continues] Polybius the historian, makes mention? And those things which Pausanius wrote concerning the Singing Stones? All these are effects of Occult Virtues. So the ostrich concocts cold and most hard iron, and digests it into nourishment for his body; whose stomach, they also report, cannot be hurt with red-hot iron. So that little fish, call echeneis, doth so curb the violence of the winds, and appease the rage of the sea, that, let the tempests be never so imperious and raging, the sails also bearing a full gale, it doth notwithstanding by its mere touch stay the ships and makes them stand still, that by no means they can be moved. So salamanders and crickets live in the fire; although they seem sometimes to burn, yet they are not hurt. The like is said of a kind of bitumen, with which the weapons of the Amazons were said to be smeared over, by which means they could be spoiled neither with sword nor fire; with which also the gates of Caspia, made of brass, are reported to be smeared over by Alexander the Great. We read also that Noah's Ark -vas joined together with this bitumen, and that it endured some thousands of years upon the Mountains of Armenia. There are many such kind of wonderful things, scarce credible, which notwithstanding are known by experience. Amongst which Antiquity makes mention of Satyrs, which were animals, in shape half men and half brutes, yet capable of speech and reason; one whereof St. Hierome reporteth, spake once unto holy Antonius the Hermit, and condemned the error of the Gentiles in worshiping such poor creatures as they were, and desired him that he would pray unto the true God for him; also he affirms that there was one of these Satyrs shewed openly alive, and afterwards sent to Constantine the Emperor.