TO HIS GRACE GEORGE, DUKE, Marquess, and Earl of BƲCKINGHAM, &c.

I PRESENT not this small Piece unto Your Grace, with so large a Confidence and good Opinion, either of my own, or its worth, as to think it a Compo∣sure Page  [unnumbered]that Merits your Patronage and Protection; it is only out of Gratitude, and a Compliance with that good and just Adage, Qui aquam hauris puteum corona. Your Grace, being the greatest and most constant Incourager, and Fautor, (that this Age hath produced) not only to Ingenuity in general, but also to my particular Self, (though the meanest of Nature's (now) Numerous Disciples.) Give me leave to make it my Op∣portunity to return an Acknow∣ledgment for that signal Honour of Your Princely Countenance, and other Favours You have been pleased to confer on me; I offer it not (My Lord) for your In∣struction, You are One whom Na∣ture hath already admitted, and Page  [unnumbered]her Self taught You in her own Schole, the Tract of her most Se∣cret Operations; and being, as You are, (even to Admiration) above others, of a most subtile and quick Apprehension; and one, who by Your own most Noble and Acute Genius, Conceptions, Ob∣servations, and constant Manual Operations, have not only disco∣ver'd the Vanity of the Galenick way, but rendred Your Self most Perfect, as well in the Practick, as Theory of Experimental Philo∣sophy, and consequently are a∣bundantly Stored, and Enriched with those two worthy and com∣mendable Attributes of the Learned, Judgment and Candor. I cannot appeal to such another Judge, and Patron: Be pleased Page  [unnumbered]therefore to accept of this my Mite, and from an improvement of my Talent, You may justly expect and challenge, and shall accordingly receive, a more large and ample Offering. In the mean time, I beg pardon for this trouble and presumption, who, in all faith∣fulness, am