[Sidenote: _How things happen to be seen as double._]
As for Polyphemus, although the story be fabulous, the monstrosity is not impossible. For the act of Vision may be performed with one eye; and in the deception and fallacy of sight, hath this advantage of two, that it beholds not objects double, or sees two things for one. For this doth happen when the axis of the visive cones, diffused from the object, fall not upon the same plane; but that which is conveyed into one eye, is more depressed or elevated then that which enters the other. So if beholding a Candle, we protrude either upward or downward the pupill of one eye, the object will appear double; but if we shut the other eye, and behold it with one, it will their appear but single; and if we abduce the eye unto either corner, the object will not duplicate: for in that position the axis of the cones remain in the same plane, as is demonstrated in the opticks, and delivered by _Galen_, in his tenth _De usu partium_.
Relations also there are of men that could make themselves invisible, which belongs not to this discourse: but may serve as notable expressions of wise and prudent men, who so contrive their affairs, that although their actions be manifest, their designs are not discoverable. In this acception there is nothing left of doubt, and _Giges_ Ring remaineth still amongst us: for vulgar eyes behold no more of wise men then doth the Sun: they may discover their exteriour and outward ways, but their interiour and inward pieces he only sees, that sees into their beings.
Concerning the _Chameleon_ there generally passeth an opinion that it liveth only upon air, and is sustained by no other aliment: Thus much is in plain terms affirmed by _Solinus_, _Pliny_, and others, and by this periphrasis is the same described by _Ovid_. All which notwithstanding, upon enquiry I find the assertion mainly controvertible, and very much to fail in the three inducements of belief.
And first for its verity, although asserted by some, and traditionally delivered by others, yet is it very questionable. For beside _Ãlian_, who is seldom defective in these accounts; _Aristotle_ distinctly treating hereof, hath made no mention of this remarkable propriety: which either suspecting its verity, or presuming its falsity, he surely omitted: for that he remained ignorant of this account it is not easily conceiveable: it being the common opinion, and generally received by all men. Some have positively denied it, as _Augustinus_, _Niphus_, _Stobæus_, _Dalechampius_, _Fortunius Licetus_, with many more; others have experimentally refuted it, as namely _Johannes Landius_, who in the relation of _Scaliger_, observed a _Chameleon_ to lick up a fly from his breast: But _Bellonius_ [SN: _Comment. in Ocell._ Lucan.] hath been more satisfactorily experimental, not only affirming they feed on Flies, Caterpillars, Beetles and other Insects, but upon exenteration he found these Animals in their bellies: whereto we might also add the experimental decisions of the worthy _Peireschius_ and learned _Emanuel Vizzanius_, in that _Chameleon_ which had been often observed to drink water, and delight to feed on Meal-worms. And although we have not had the advantage of our own observation, yet have we received the like confirmation from many ocular spectators.