And that their motion seems (contrary to what we may observe in the motion of all other Infects) exceeding slow.  But the reason of it seems plain, for being to move to and fro after that manner which they do, by waving onely, or wrigling their body; the tenacity, or glutinousness, and the density or resistance of the fluid medium becomes so exceeding sensible to their extremely minute bodies, that it is to me indeed a greater wonder that they move them so fast as they do, then that they move them no faster.  For what a vastly greater proportion have they of their superficies to their bulk, then Eels or other larger Fishes, and next, the tenacity and density of the liquor being much the same to be moved, both by the one and the other, the resistance or impediment thence arising to the motions made through it, must be almost infinitely greater to the small one then to the great.  This we find experimentally verify’d in the Air, which though a medium a thousand times more rarify’d then the water, the resistance of it to motions made through it, is yet so sensible to very minute bodies, that a Down-feather (the least of whose parts seem yet bigger then these Eels, and many of them almost incomparably bigger, such as the quill and stalk) is suspended by it, and carried to and fro as if it had no weight.

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Observ.  LVIII. Of a new Property in the Air_, and several other transparent Mediums nam’d Inflection, whereby very many considerable Phaenomena are attempted to be solv’d, and divers other uses are hinted._

Since the Invention (and perfecting in some measure) of Telescopes, it has been observ’d by several, that the Sun and Moon neer the Horizon, are disfigur’d (losing that exactly-smooth terminating circular limb, which they are observ’d to have when situated neerer the Zenith) and are bounded with an edge every way (especially upon the right and left sides) ragged and indented like a Saw:  which inequality of their limbs, I have further observ’d, not to remain always the same, but to be continually chang’d by a kind of fluctuating motion, not unlike that of the waves of the Sea, so as that part of the limb, which was but even now nick’d or indented in, is now protuberant, and will presently be sinking again; neither is this all but the whole body of the Luminaries, do in the Telescope, seem to be depress’d and slatted, the upper, and more especially the under side appearing neerer to the middle then really they are, and the right and left appearing more remote:  whence the whole Area seems to be terminated by a kind of Oval.  It is further observ’d, that the body, for the most part, appears red, or of some colour approaching neer unto it, as some kind of yellow; and this I have always mark’d, that the more the limb is slatted or ovalled, the more red does the body appear, though not always the contrary.  It is further observable,